[PATCH v7 00/12] create sysfs files for changing IP address

[PATCH v7 00/12] create sysfs files for changing IP address

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

v7: change client's link to hardcoded "switch"

Anna Schumaker (3):
  sunrpc: Create a sunrpc directory under /sys/kernel/
  sunrpc: Create a client/ subdirectory in the sunrpc sysfs
  sunrpc: Create per-rpc_clnt sysfs kobjects

Dan Aloni (2):
  sunrpc: add xprt id
  sunrpc: add IDs to multipath

Olga Kornievskaia (7):
  sunrpc: keep track of the xprt_class in rpc_xprt structure
  sunrpc: add xprt_switch direcotry to sunrpc's sysfs
  sunrpc: add a symlink from rpc-client directory to the xprt_switch
  sunrpc: add add sysfs directory per xprt under each xprt_switch
  sunrpc: add dst_attr attributes to the sysfs xprt directory
  sunrpc: provide transport info in the sysfs directory
  sunrpc: provide multipath info in the sysfs directory

 include/linux/sunrpc/clnt.h          |   2 +
 include/linux/sunrpc/xprt.h          |   7 +
 include/linux/sunrpc/xprtmultipath.h |   6 +
 net/sunrpc/Makefile                  |   2 +-
 net/sunrpc/clnt.c                    |   5 +
 net/sunrpc/sunrpc_syms.c             |  10 +
 net/sunrpc/sysfs.c                   | 482 +++++++++++++++++++++++++++
 net/sunrpc/sysfs.h                   |  41 +++
 net/sunrpc/xprt.c                    |  28 +-
 net/sunrpc/xprtmultipath.c           |  34 ++
 net/sunrpc/xprtrdma/transport.c      |   2 +
 net/sunrpc/xprtsock.c                |   9 +
 12 files changed, 626 insertions(+), 2 deletions(-)
 create mode 100644 net/sunrpc/sysfs.c
 create mode 100644 net/sunrpc/sysfs.h

-- 
2.27.0

[PATCH v7 01/12] sunrpc: Create a sunrpc directory under /sys/kernel/

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

This is where we'll put per-rpc_client related files

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 net/sunrpc/Makefile      |  2 +-
 net/sunrpc/sunrpc_syms.c |  8 ++++++++
 net/sunrpc/sysfs.c       | 20 ++++++++++++++++++++
 net/sunrpc/sysfs.h       | 11 +++++++++++
 4 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 net/sunrpc/sysfs.c
 create mode 100644 net/sunrpc/sysfs.h

diff --git a/net/sunrpc/Makefile b/net/sunrpc/Makefile
index 9488600451e8..1c8de397d6ad 100644
--- a/net/sunrpc/Makefile
+++ b/net/sunrpc/Makefile
@@ -12,7 +12,7 @@ sunrpc-y := clnt.o xprt.o socklib.o xprtsock.o sched.o \
 	    auth.o auth_null.o auth_unix.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 \
+	    sunrpc_syms.o cache.o rpc_pipe.o sysfs.o \
 	    svc_xprt.o \
 	    xprtmultipath.o
 sunrpc-$(CONFIG_SUNRPC_DEBUG) += debugfs.o
diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c
index 236fadc4a439..3b57efc692ec 100644
--- a/net/sunrpc/sunrpc_syms.c
+++ b/net/sunrpc/sunrpc_syms.c
@@ -24,6 +24,7 @@
 #include <linux/sunrpc/xprtsock.h>
 
 #include "sunrpc.h"
+#include "sysfs.h"
 #include "netns.h"
 
 unsigned int sunrpc_net_id;
@@ -103,6 +104,10 @@ init_sunrpc(void)
 	if (err)
 		goto out4;
 
+	err = rpc_sysfs_init();
+	if (err)
+		goto out5;
+
 	sunrpc_debugfs_init();
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 	rpc_register_sysctl();
@@ -111,6 +116,8 @@ init_sunrpc(void)
 	init_socket_xprt();	/* clnt sock transport */
 	return 0;
 
+out5:
+	unregister_rpc_pipefs();
 out4:
 	unregister_pernet_subsys(&sunrpc_net_ops);
 out3:
@@ -124,6 +131,7 @@ init_sunrpc(void)
 static void __exit
 cleanup_sunrpc(void)
 {
+	rpc_sysfs_exit();
 	rpc_cleanup_clids();
 	rpcauth_remove_module();
 	cleanup_socket_xprt();
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
new file mode 100644
index 000000000000..27eda180ac5e
--- /dev/null
+++ b/net/sunrpc/sysfs.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Anna Schumaker <Anna.Schumaker@Netapp.com>
+ */
+#include <linux/kobject.h>
+
+static struct kset *rpc_sunrpc_kset;
+
+int rpc_sysfs_init(void)
+{
+	rpc_sunrpc_kset = kset_create_and_add("sunrpc", NULL, kernel_kobj);
+	if (!rpc_sunrpc_kset)
+		return -ENOMEM;
+	return 0;
+}
+
+void rpc_sysfs_exit(void)
+{
+	kset_unregister(rpc_sunrpc_kset);
+}
diff --git a/net/sunrpc/sysfs.h b/net/sunrpc/sysfs.h
new file mode 100644
index 000000000000..f181c650aab8
--- /dev/null
+++ b/net/sunrpc/sysfs.h
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Anna Schumaker <Anna.Schumaker@Netapp.com>
+ */
+#ifndef __SUNRPC_SYSFS_H
+#define __SUNRPC_SYSFS_H
+
+int rpc_sysfs_init(void);
+void rpc_sysfs_exit(void);
+
+#endif
-- 
2.27.0

[PATCH v7 02/12] sunrpc: Create a client/ subdirectory in the sunrpc sysfs

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

For network namespace separation.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 net/sunrpc/sysfs.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index 27eda180ac5e..fa03e2ef836a 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -2,19 +2,62 @@
 /*
  * Copyright (c) 2020 Anna Schumaker <Anna.Schumaker@Netapp.com>
  */
+#include <linux/sunrpc/clnt.h>
 #include <linux/kobject.h>
 
 static struct kset *rpc_sunrpc_kset;
+static struct kobject *rpc_sunrpc_client_kobj;
+
+static void rpc_sysfs_object_release(struct kobject *kobj)
+{
+	kfree(kobj);
+}
+
+static const struct kobj_ns_type_operations *
+rpc_sysfs_object_child_ns_type(struct kobject *kobj)
+{
+	return &net_ns_type_operations;
+}
+
+static struct kobj_type rpc_sysfs_object_type = {
+	.release = rpc_sysfs_object_release,
+	.sysfs_ops = &kobj_sysfs_ops,
+	.child_ns_type = rpc_sysfs_object_child_ns_type,
+};
+
+static struct kobject *rpc_sysfs_object_alloc(const char *name,
+					      struct kset *kset,
+					      struct kobject *parent)
+{
+	struct kobject *kobj;
+
+	kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
+	if (kobj) {
+		kobj->kset = kset;
+		if (kobject_init_and_add(kobj, &rpc_sysfs_object_type,
+					 parent, "%s", name) == 0)
+			return kobj;
+		kobject_put(kobj);
+	}
+	return NULL;
+}
 
 int rpc_sysfs_init(void)
 {
 	rpc_sunrpc_kset = kset_create_and_add("sunrpc", NULL, kernel_kobj);
 	if (!rpc_sunrpc_kset)
 		return -ENOMEM;
+	rpc_sunrpc_client_kobj = rpc_sysfs_object_alloc("client", rpc_sunrpc_kset, NULL);
+	if (!rpc_sunrpc_client_kobj) {
+		kset_unregister(rpc_sunrpc_kset);
+		rpc_sunrpc_client_kobj = NULL;
+		return -ENOMEM;
+	}
 	return 0;
 }
 
 void rpc_sysfs_exit(void)
 {
+	kobject_put(rpc_sunrpc_client_kobj);
 	kset_unregister(rpc_sunrpc_kset);
 }
-- 
2.27.0

[PATCH v7 03/12] sunrpc: Create per-rpc_clnt sysfs kobjects

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

These will eventually have files placed under them for sysfs operations.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 include/linux/sunrpc/clnt.h |  2 ++
 net/sunrpc/clnt.c           |  5 +++
 net/sunrpc/sysfs.c          | 61 +++++++++++++++++++++++++++++++++++++
 net/sunrpc/sysfs.h          |  8 +++++
 4 files changed, 76 insertions(+)

diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index 02e7a5863d28..8b5d5c97553e 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -29,6 +29,7 @@
 #include <linux/sunrpc/xprtmultipath.h>
 
 struct rpc_inode;
+struct rpc_sysfs_client;
 
 /*
  * The high-level client handle
@@ -71,6 +72,7 @@ struct rpc_clnt {
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 	struct dentry		*cl_debugfs;	/* debugfs directory */
 #endif
+	struct rpc_sysfs_client *cl_sysfs;	/* sysfs directory */
 	/* cl_work is only needed after cl_xpi is no longer used,
 	 * and that are of similar size
 	 */
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index f555d335e910..ec9254a11a03 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -41,6 +41,7 @@
 #include <trace/events/sunrpc.h>
 
 #include "sunrpc.h"
+#include "sysfs.h"
 #include "netns.h"
 
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
@@ -300,6 +301,7 @@ static int rpc_client_register(struct rpc_clnt *clnt,
 	int err;
 
 	rpc_clnt_debugfs_register(clnt);
+	rpc_sysfs_client_setup(clnt, net);
 
 	pipefs_sb = rpc_get_sb_net(net);
 	if (pipefs_sb) {
@@ -327,6 +329,7 @@ static int rpc_client_register(struct rpc_clnt *clnt,
 out:
 	if (pipefs_sb)
 		rpc_put_sb_net(net);
+	rpc_sysfs_client_destroy(clnt);
 	rpc_clnt_debugfs_unregister(clnt);
 	return err;
 }
@@ -733,6 +736,7 @@ int rpc_switch_client_transport(struct rpc_clnt *clnt,
 
 	rpc_unregister_client(clnt);
 	__rpc_clnt_remove_pipedir(clnt);
+	rpc_sysfs_client_destroy(clnt);
 	rpc_clnt_debugfs_unregister(clnt);
 
 	/*
@@ -879,6 +883,7 @@ static void rpc_free_client_work(struct work_struct *work)
 	 * so they cannot be called in rpciod, so they are handled separately
 	 * here.
 	 */
+	rpc_sysfs_client_destroy(clnt);
 	rpc_clnt_debugfs_unregister(clnt);
 	rpc_free_clid(clnt);
 	rpc_clnt_remove_pipedir(clnt);
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index fa03e2ef836a..f3b7547ee218 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -4,6 +4,7 @@
  */
 #include <linux/sunrpc/clnt.h>
 #include <linux/kobject.h>
+#include "sysfs.h"
 
 static struct kset *rpc_sunrpc_kset;
 static struct kobject *rpc_sunrpc_client_kobj;
@@ -56,8 +57,68 @@ int rpc_sysfs_init(void)
 	return 0;
 }
 
+static void rpc_sysfs_client_release(struct kobject *kobj)
+{
+	struct rpc_sysfs_client *c;
+
+	c = container_of(kobj, struct rpc_sysfs_client, kobject);
+	kfree(c);
+}
+
+static const void *rpc_sysfs_client_namespace(struct kobject *kobj)
+{
+	return container_of(kobj, struct rpc_sysfs_client, kobject)->net;
+}
+
+static struct kobj_type rpc_sysfs_client_type = {
+	.release = rpc_sysfs_client_release,
+	.sysfs_ops = &kobj_sysfs_ops,
+	.namespace = rpc_sysfs_client_namespace,
+};
+
 void rpc_sysfs_exit(void)
 {
 	kobject_put(rpc_sunrpc_client_kobj);
 	kset_unregister(rpc_sunrpc_kset);
 }
+
+static struct rpc_sysfs_client *rpc_sysfs_client_alloc(struct kobject *parent,
+						       struct net *net,
+						       int clid)
+{
+	struct rpc_sysfs_client *p;
+
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	if (p) {
+		p->net = net;
+		p->kobject.kset = rpc_sunrpc_kset;
+		if (kobject_init_and_add(&p->kobject, &rpc_sysfs_client_type,
+					 parent, "clnt-%d", clid) == 0)
+			return p;
+		kobject_put(&p->kobject);
+	}
+	return NULL;
+}
+
+void rpc_sysfs_client_setup(struct rpc_clnt *clnt, struct net *net)
+{
+	struct rpc_sysfs_client *rpc_client;
+
+	rpc_client = rpc_sysfs_client_alloc(rpc_sunrpc_client_kobj, net, clnt->cl_clid);
+	if (rpc_client) {
+		clnt->cl_sysfs = rpc_client;
+		kobject_uevent(&rpc_client->kobject, KOBJ_ADD);
+	}
+}
+
+void rpc_sysfs_client_destroy(struct rpc_clnt *clnt)
+{
+	struct rpc_sysfs_client *rpc_client = clnt->cl_sysfs;
+
+	if (rpc_client) {
+		kobject_uevent(&rpc_client->kobject, KOBJ_REMOVE);
+		kobject_del(&rpc_client->kobject);
+		kobject_put(&rpc_client->kobject);
+		clnt->cl_sysfs = NULL;
+	}
+}
diff --git a/net/sunrpc/sysfs.h b/net/sunrpc/sysfs.h
index f181c650aab8..c46afc848993 100644
--- a/net/sunrpc/sysfs.h
+++ b/net/sunrpc/sysfs.h
@@ -5,7 +5,15 @@
 #ifndef __SUNRPC_SYSFS_H
 #define __SUNRPC_SYSFS_H
 
+struct rpc_sysfs_client {
+	struct kobject kobject;
+	struct net *net;
+};
+
 int rpc_sysfs_init(void);
 void rpc_sysfs_exit(void);
 
+void rpc_sysfs_client_setup(struct rpc_clnt *clnt, struct net *net);
+void rpc_sysfs_client_destroy(struct rpc_clnt *clnt);
+
 #endif
-- 
2.27.0

[PATCH v7 04/12] sunrpc: add xprt id

[Olga Kornievskaia]

From: Dan Aloni <dan@kernelim.com>

This adds a unique identifier for a sunrpc transport in sysfs, which is
similarly managed to the unique IDs of clients.

Signed-off-by: Dan Aloni <dan@kernelim.com>
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 include/linux/sunrpc/xprt.h |  2 ++
 net/sunrpc/sunrpc_syms.c    |  1 +
 net/sunrpc/xprt.c           | 26 ++++++++++++++++++++++++++
 3 files changed, 29 insertions(+)

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index d81fe8b364d0..82294d06075c 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -185,6 +185,7 @@ enum xprt_transports {
 struct rpc_xprt {
 	struct kref		kref;		/* Reference count */
 	const struct rpc_xprt_ops *ops;		/* transport methods */
+	unsigned int		id;		/* transport id */
 
 	const struct rpc_timeout *timeout;	/* timeout parms */
 	struct sockaddr_storage	addr;		/* server address */
@@ -368,6 +369,7 @@ 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 *);
+void			xprt_cleanup_ids(void);
 
 static inline int
 xprt_enable_swap(struct rpc_xprt *xprt)
diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c
index 3b57efc692ec..b61b74c00483 100644
--- a/net/sunrpc/sunrpc_syms.c
+++ b/net/sunrpc/sunrpc_syms.c
@@ -133,6 +133,7 @@ cleanup_sunrpc(void)
 {
 	rpc_sysfs_exit();
 	rpc_cleanup_clids();
+	xprt_cleanup_ids();
 	rpcauth_remove_module();
 	cleanup_socket_xprt();
 	svc_cleanup_xprt_sock();
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index e5b5a960a69b..fd58a3a16add 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -1722,6 +1722,30 @@ static void xprt_free_all_slots(struct rpc_xprt *xprt)
 	}
 }
 
+static DEFINE_IDA(rpc_xprt_ids);
+
+void xprt_cleanup_ids(void)
+{
+	ida_destroy(&rpc_xprt_ids);
+}
+
+static int xprt_alloc_id(struct rpc_xprt *xprt)
+{
+	int id;
+
+	id = ida_simple_get(&rpc_xprt_ids, 0, 0, GFP_KERNEL);
+	if (id < 0)
+		return id;
+
+	xprt->id = id;
+	return 0;
+}
+
+static void xprt_free_id(struct rpc_xprt *xprt)
+{
+	ida_simple_remove(&rpc_xprt_ids, xprt->id);
+}
+
 struct rpc_xprt *xprt_alloc(struct net *net, size_t size,
 		unsigned int num_prealloc,
 		unsigned int max_alloc)
@@ -1734,6 +1758,7 @@ struct rpc_xprt *xprt_alloc(struct net *net, size_t size,
 	if (xprt == NULL)
 		goto out;
 
+	xprt_alloc_id(xprt);
 	xprt_init(xprt, net);
 
 	for (i = 0; i < num_prealloc; i++) {
@@ -1762,6 +1787,7 @@ void xprt_free(struct rpc_xprt *xprt)
 {
 	put_net(xprt->xprt_net);
 	xprt_free_all_slots(xprt);
+	xprt_free_id(xprt);
 	kfree_rcu(xprt, rcu);
 }
 EXPORT_SYMBOL_GPL(xprt_free);
-- 
2.27.0

[PATCH v7 05/12] sunrpc: add IDs to multipath

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

This is used to uniquely identify sunrpc multipath objects in /sys.

Signed-off-by: Dan Aloni <dan@kernelim.com>
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 include/linux/sunrpc/xprtmultipath.h |  4 ++++
 net/sunrpc/sunrpc_syms.c             |  1 +
 net/sunrpc/xprtmultipath.c           | 26 ++++++++++++++++++++++++++
 3 files changed, 31 insertions(+)

diff --git a/include/linux/sunrpc/xprtmultipath.h b/include/linux/sunrpc/xprtmultipath.h
index c6cce3fbf29d..ef95a6f18ccf 100644
--- a/include/linux/sunrpc/xprtmultipath.h
+++ b/include/linux/sunrpc/xprtmultipath.h
@@ -14,6 +14,7 @@ struct rpc_xprt_switch {
 	spinlock_t		xps_lock;
 	struct kref		xps_kref;
 
+	unsigned int		xps_id;
 	unsigned int		xps_nxprts;
 	unsigned int		xps_nactive;
 	atomic_long_t		xps_queuelen;
@@ -71,4 +72,7 @@ extern struct rpc_xprt *xprt_iter_get_next(struct rpc_xprt_iter *xpi);
 
 extern bool rpc_xprt_switch_has_addr(struct rpc_xprt_switch *xps,
 		const struct sockaddr *sap);
+
+extern void xprt_multipath_cleanup_ids(void);
+
 #endif
diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c
index b61b74c00483..691c0000e9ea 100644
--- a/net/sunrpc/sunrpc_syms.c
+++ b/net/sunrpc/sunrpc_syms.c
@@ -134,6 +134,7 @@ cleanup_sunrpc(void)
 	rpc_sysfs_exit();
 	rpc_cleanup_clids();
 	xprt_cleanup_ids();
+	xprt_multipath_cleanup_ids();
 	rpcauth_remove_module();
 	cleanup_socket_xprt();
 	svc_cleanup_xprt_sock();
diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c
index 78c075a68c04..4969a4c216f7 100644
--- a/net/sunrpc/xprtmultipath.c
+++ b/net/sunrpc/xprtmultipath.c
@@ -86,6 +86,30 @@ void rpc_xprt_switch_remove_xprt(struct rpc_xprt_switch *xps,
 	xprt_put(xprt);
 }
 
+static DEFINE_IDA(rpc_xprtswitch_ids);
+
+void xprt_multipath_cleanup_ids(void)
+{
+	ida_destroy(&rpc_xprtswitch_ids);
+}
+
+static int xprt_switch_alloc_id(struct rpc_xprt_switch *xps, gfp_t gfp_flags)
+{
+	int id;
+
+	id = ida_simple_get(&rpc_xprtswitch_ids, 0, 0, gfp_flags);
+	if (id < 0)
+		return id;
+
+	xps->xps_id = id;
+	return 0;
+}
+
+static void xprt_switch_free_id(struct rpc_xprt_switch *xps)
+{
+	ida_simple_remove(&rpc_xprtswitch_ids, xps->xps_id);
+}
+
 /**
  * xprt_switch_alloc - Allocate a new struct rpc_xprt_switch
  * @xprt: pointer to struct rpc_xprt
@@ -103,6 +127,7 @@ struct rpc_xprt_switch *xprt_switch_alloc(struct rpc_xprt *xprt,
 	if (xps != NULL) {
 		spin_lock_init(&xps->xps_lock);
 		kref_init(&xps->xps_kref);
+		xprt_switch_alloc_id(xps, gfp_flags);
 		xps->xps_nxprts = xps->xps_nactive = 0;
 		atomic_long_set(&xps->xps_queuelen, 0);
 		xps->xps_net = NULL;
@@ -136,6 +161,7 @@ static void xprt_switch_free(struct kref *kref)
 			struct rpc_xprt_switch, xps_kref);
 
 	xprt_switch_free_entries(xps);
+	xprt_switch_free_id(xps);
 	kfree_rcu(xps, xps_rcu);
 }
 
-- 
2.27.0

[PATCH v7 06/12] sunrpc: keep track of the xprt_class in rpc_xprt structure

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

We need to keep track of the type for a given transport.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 include/linux/sunrpc/xprt.h     | 2 ++
 net/sunrpc/xprtrdma/transport.c | 2 ++
 net/sunrpc/xprtsock.c           | 9 +++++++++
 3 files changed, 13 insertions(+)

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 82294d06075c..a2edcc42e6c4 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -53,6 +53,7 @@ enum rpc_display_format_t {
 
 struct rpc_task;
 struct rpc_xprt;
+struct xprt_class;
 struct seq_file;
 struct svc_serv;
 struct net;
@@ -289,6 +290,7 @@ struct rpc_xprt {
 	atomic_t		inject_disconnect;
 #endif
 	struct rcu_head		rcu;
+	const struct xprt_class	*xprt_class;
 };
 
 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 09953597d055..71500eb89bff 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -73,6 +73,7 @@ unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
 unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
 unsigned int xprt_rdma_memreg_strategy		= RPCRDMA_FRWR;
 int xprt_rdma_pad_optimize;
+static struct xprt_class xprt_rdma;
 
 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 
@@ -349,6 +350,7 @@ xprt_setup_rdma(struct xprt_create *args)
 	/* Ensure xprt->addr holds valid server TCP (not RDMA)
 	 * address, for any side protocols which peek at it */
 	xprt->prot = IPPROTO_TCP;
+	xprt->xprt_class = &xprt_rdma;
 	xprt->addrlen = args->addrlen;
 	memcpy(&xprt->addr, sap, xprt->addrlen);
 
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 47aa47a2b07c..f02a61bc0d95 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -91,6 +91,11 @@ static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
 
 static struct ctl_table_header *sunrpc_table_header;
 
+static struct xprt_class xs_local_transport;
+static struct xprt_class xs_udp_transport;
+static struct xprt_class xs_tcp_transport;
+static struct xprt_class xs_bc_tcp_transport;
+
 /*
  * FIXME: changing the UDP slot table size should also resize the UDP
  *        socket buffers for existing UDP transports
@@ -2777,6 +2782,7 @@ static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
 	transport = container_of(xprt, struct sock_xprt, xprt);
 
 	xprt->prot = 0;
+	xprt->xprt_class = &xs_local_transport;
 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
 
 	xprt->bind_timeout = XS_BIND_TO;
@@ -2846,6 +2852,7 @@ static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
 	transport = container_of(xprt, struct sock_xprt, xprt);
 
 	xprt->prot = IPPROTO_UDP;
+	xprt->xprt_class = &xs_udp_transport;
 	/* XXX: header size can vary due to auth type, IPv6, etc. */
 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
 
@@ -2926,6 +2933,7 @@ static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
 	transport = container_of(xprt, struct sock_xprt, xprt);
 
 	xprt->prot = IPPROTO_TCP;
+	xprt->xprt_class = &xs_tcp_transport;
 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
 
 	xprt->bind_timeout = XS_BIND_TO;
@@ -2999,6 +3007,7 @@ static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
 	transport = container_of(xprt, struct sock_xprt, xprt);
 
 	xprt->prot = IPPROTO_TCP;
+	xprt->xprt_class = &xs_bc_tcp_transport;
 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
 	xprt->timeout = &xs_tcp_default_timeout;
 
-- 
2.27.0

[PATCH v7 07/12] sunrpc: add xprt_switch direcotry to sunrpc's sysfs

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

Add xprt_switch directory to the sysfs and create individual
xprt_swith subdirectories for multipath transport group.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 include/linux/sunrpc/xprtmultipath.h |  2 +
 net/sunrpc/sysfs.c                   | 99 ++++++++++++++++++++++++++--
 net/sunrpc/sysfs.h                   | 10 +++
 net/sunrpc/xprtmultipath.c           |  4 ++
 4 files changed, 108 insertions(+), 7 deletions(-)

diff --git a/include/linux/sunrpc/xprtmultipath.h b/include/linux/sunrpc/xprtmultipath.h
index ef95a6f18ccf..b19addc8b715 100644
--- a/include/linux/sunrpc/xprtmultipath.h
+++ b/include/linux/sunrpc/xprtmultipath.h
@@ -10,6 +10,7 @@
 #define _NET_SUNRPC_XPRTMULTIPATH_H
 
 struct rpc_xprt_iter_ops;
+struct rpc_sysfs_xprt_switch;
 struct rpc_xprt_switch {
 	spinlock_t		xps_lock;
 	struct kref		xps_kref;
@@ -24,6 +25,7 @@ struct rpc_xprt_switch {
 
 	const struct rpc_xprt_iter_ops *xps_iter_ops;
 
+	struct rpc_sysfs_xprt_switch *xps_sysfs;
 	struct rcu_head		xps_rcu;
 };
 
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index f3b7547ee218..ed9f7131543f 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -7,7 +7,7 @@
 #include "sysfs.h"
 
 static struct kset *rpc_sunrpc_kset;
-static struct kobject *rpc_sunrpc_client_kobj;
+static struct kobject *rpc_sunrpc_client_kobj, *rpc_sunrpc_xprt_switch_kobj;
 
 static void rpc_sysfs_object_release(struct kobject *kobj)
 {
@@ -48,13 +48,22 @@ int rpc_sysfs_init(void)
 	rpc_sunrpc_kset = kset_create_and_add("sunrpc", NULL, kernel_kobj);
 	if (!rpc_sunrpc_kset)
 		return -ENOMEM;
-	rpc_sunrpc_client_kobj = rpc_sysfs_object_alloc("client", rpc_sunrpc_kset, NULL);
-	if (!rpc_sunrpc_client_kobj) {
-		kset_unregister(rpc_sunrpc_kset);
-		rpc_sunrpc_client_kobj = NULL;
-		return -ENOMEM;
-	}
+	rpc_sunrpc_client_kobj =
+		rpc_sysfs_object_alloc("rpc-clients", rpc_sunrpc_kset, NULL);
+	if (!rpc_sunrpc_client_kobj)
+		goto err_client;
+	rpc_sunrpc_xprt_switch_kobj =
+		rpc_sysfs_object_alloc("xprt-switches", rpc_sunrpc_kset, NULL);
+	if (!rpc_sunrpc_xprt_switch_kobj)
+		goto err_switch;
 	return 0;
+err_switch:
+	kobject_put(rpc_sunrpc_client_kobj);
+	rpc_sunrpc_client_kobj = NULL;
+err_client:
+	kset_unregister(rpc_sunrpc_kset);
+	rpc_sunrpc_kset = NULL;
+	return -ENOMEM;
 }
 
 static void rpc_sysfs_client_release(struct kobject *kobj)
@@ -65,20 +74,40 @@ static void rpc_sysfs_client_release(struct kobject *kobj)
 	kfree(c);
 }
 
+static void rpc_sysfs_xprt_switch_release(struct kobject *kobj)
+{
+	struct rpc_sysfs_xprt_switch *xprt_switch;
+
+	xprt_switch = container_of(kobj, struct rpc_sysfs_xprt_switch, kobject);
+	kfree(xprt_switch);
+}
+
 static const void *rpc_sysfs_client_namespace(struct kobject *kobj)
 {
 	return container_of(kobj, struct rpc_sysfs_client, kobject)->net;
 }
 
+static const void *rpc_sysfs_xprt_switch_namespace(struct kobject *kobj)
+{
+	return container_of(kobj, struct rpc_sysfs_xprt_switch, kobject)->net;
+}
+
 static struct kobj_type rpc_sysfs_client_type = {
 	.release = rpc_sysfs_client_release,
 	.sysfs_ops = &kobj_sysfs_ops,
 	.namespace = rpc_sysfs_client_namespace,
 };
 
+static struct kobj_type rpc_sysfs_xprt_switch_type = {
+	.release = rpc_sysfs_xprt_switch_release,
+	.sysfs_ops = &kobj_sysfs_ops,
+	.namespace = rpc_sysfs_xprt_switch_namespace,
+};
+
 void rpc_sysfs_exit(void)
 {
 	kobject_put(rpc_sunrpc_client_kobj);
+	kobject_put(rpc_sunrpc_xprt_switch_kobj);
 	kset_unregister(rpc_sunrpc_kset);
 }
 
@@ -100,6 +129,28 @@ static struct rpc_sysfs_client *rpc_sysfs_client_alloc(struct kobject *parent,
 	return NULL;
 }
 
+static struct rpc_sysfs_xprt_switch *
+rpc_sysfs_xprt_switch_alloc(struct kobject *parent,
+			    struct rpc_xprt_switch *xprt_switch,
+			    struct net *net,
+			    gfp_t gfp_flags)
+{
+	struct rpc_sysfs_xprt_switch *p;
+
+	p = kzalloc(sizeof(*p), gfp_flags);
+	if (p) {
+		p->net = net;
+		p->kobject.kset = rpc_sunrpc_kset;
+		if (kobject_init_and_add(&p->kobject,
+					 &rpc_sysfs_xprt_switch_type,
+					 parent, "switch-%d",
+					 xprt_switch->xps_id) == 0)
+			return p;
+		kobject_put(&p->kobject);
+	}
+	return NULL;
+}
+
 void rpc_sysfs_client_setup(struct rpc_clnt *clnt, struct net *net)
 {
 	struct rpc_sysfs_client *rpc_client;
@@ -111,6 +162,28 @@ void rpc_sysfs_client_setup(struct rpc_clnt *clnt, struct net *net)
 	}
 }
 
+void rpc_sysfs_xprt_switch_setup(struct rpc_xprt_switch *xprt_switch,
+				 struct rpc_xprt *xprt,
+				 gfp_t gfp_flags)
+{
+	struct rpc_sysfs_xprt_switch *rpc_xprt_switch;
+	struct net *net;
+
+	if (xprt_switch->xps_net)
+		net = xprt_switch->xps_net;
+	else
+		net = xprt->xprt_net;
+	rpc_xprt_switch =
+		rpc_sysfs_xprt_switch_alloc(rpc_sunrpc_xprt_switch_kobj,
+					    xprt_switch, net, gfp_flags);
+	if (rpc_xprt_switch) {
+		xprt_switch->xps_sysfs = rpc_xprt_switch;
+		rpc_xprt_switch->xprt_switch = xprt_switch;
+		rpc_xprt_switch->xprt = xprt;
+		kobject_uevent(&rpc_xprt_switch->kobject, KOBJ_ADD);
+	}
+}
+
 void rpc_sysfs_client_destroy(struct rpc_clnt *clnt)
 {
 	struct rpc_sysfs_client *rpc_client = clnt->cl_sysfs;
@@ -122,3 +195,15 @@ void rpc_sysfs_client_destroy(struct rpc_clnt *clnt)
 		clnt->cl_sysfs = NULL;
 	}
 }
+
+void rpc_sysfs_xprt_switch_destroy(struct rpc_xprt_switch *xprt_switch)
+{
+	struct rpc_sysfs_xprt_switch *rpc_xprt_switch = xprt_switch->xps_sysfs;
+
+	if (rpc_xprt_switch) {
+		kobject_uevent(&rpc_xprt_switch->kobject, KOBJ_REMOVE);
+		kobject_del(&rpc_xprt_switch->kobject);
+		kobject_put(&rpc_xprt_switch->kobject);
+		xprt_switch->xps_sysfs = NULL;
+	}
+}
diff --git a/net/sunrpc/sysfs.h b/net/sunrpc/sysfs.h
index c46afc848993..52ec472bd4a9 100644
--- a/net/sunrpc/sysfs.h
+++ b/net/sunrpc/sysfs.h
@@ -10,10 +10,20 @@ struct rpc_sysfs_client {
 	struct net *net;
 };
 
+struct rpc_sysfs_xprt_switch {
+	struct kobject kobject;
+	struct net *net;
+	struct rpc_xprt_switch *xprt_switch;
+	struct rpc_xprt *xprt;
+};
+
 int rpc_sysfs_init(void);
 void rpc_sysfs_exit(void);
 
 void rpc_sysfs_client_setup(struct rpc_clnt *clnt, struct net *net);
 void rpc_sysfs_client_destroy(struct rpc_clnt *clnt);
+void rpc_sysfs_xprt_switch_setup(struct rpc_xprt_switch *xprt_switch,
+				 struct rpc_xprt *xprt, gfp_t gfp_flags);
+void rpc_sysfs_xprt_switch_destroy(struct rpc_xprt_switch *xprt);
 
 #endif
diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c
index 4969a4c216f7..2d73a35df9ee 100644
--- a/net/sunrpc/xprtmultipath.c
+++ b/net/sunrpc/xprtmultipath.c
@@ -19,6 +19,8 @@
 #include <linux/sunrpc/addr.h>
 #include <linux/sunrpc/xprtmultipath.h>
 
+#include "sysfs.h"
+
 typedef struct rpc_xprt *(*xprt_switch_find_xprt_t)(struct rpc_xprt_switch *xps,
 		const struct rpc_xprt *cur);
 
@@ -133,6 +135,7 @@ struct rpc_xprt_switch *xprt_switch_alloc(struct rpc_xprt *xprt,
 		xps->xps_net = NULL;
 		INIT_LIST_HEAD(&xps->xps_xprt_list);
 		xps->xps_iter_ops = &rpc_xprt_iter_singular;
+		rpc_sysfs_xprt_switch_setup(xps, xprt, gfp_flags);
 		xprt_switch_add_xprt_locked(xps, xprt);
 	}
 
@@ -161,6 +164,7 @@ static void xprt_switch_free(struct kref *kref)
 			struct rpc_xprt_switch, xps_kref);
 
 	xprt_switch_free_entries(xps);
+	rpc_sysfs_xprt_switch_destroy(xps);
 	xprt_switch_free_id(xps);
 	kfree_rcu(xps, xps_rcu);
 }
-- 
2.27.0

[PATCH v7 08/12] sunrpc: add a symlink from rpc-client directory to the xprt_switch

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

An rpc client uses a transport switch and one ore more transports
associated with that switch. Since transports are shared among
rpc clients, create a symlink into the xprt_switch directory
instead of duplicating entries under each rpc client.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 net/sunrpc/clnt.c  |  2 +-
 net/sunrpc/sysfs.c | 22 ++++++++++++++++++++--
 net/sunrpc/sysfs.h |  6 +++++-
 3 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index ec9254a11a03..277db7fd0fcd 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -301,7 +301,6 @@ static int rpc_client_register(struct rpc_clnt *clnt,
 	int err;
 
 	rpc_clnt_debugfs_register(clnt);
-	rpc_sysfs_client_setup(clnt, net);
 
 	pipefs_sb = rpc_get_sb_net(net);
 	if (pipefs_sb) {
@@ -426,6 +425,7 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 	/* save the nodename */
 	rpc_clnt_set_nodename(clnt, nodename);
 
+	rpc_sysfs_client_setup(clnt, xps, rpc_net_ns(clnt));
 	err = rpc_client_register(clnt, args->authflavor, args->client_name);
 	if (err)
 		goto out_no_path;
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index ed9f7131543f..0aa63747f496 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -151,14 +151,29 @@ rpc_sysfs_xprt_switch_alloc(struct kobject *parent,
 	return NULL;
 }
 
-void rpc_sysfs_client_setup(struct rpc_clnt *clnt, struct net *net)
+void rpc_sysfs_client_setup(struct rpc_clnt *clnt,
+			    struct rpc_xprt_switch *xprt_switch,
+			    struct net *net)
 {
 	struct rpc_sysfs_client *rpc_client;
 
-	rpc_client = rpc_sysfs_client_alloc(rpc_sunrpc_client_kobj, net, clnt->cl_clid);
+	rpc_client = rpc_sysfs_client_alloc(rpc_sunrpc_client_kobj,
+					    net, clnt->cl_clid);
 	if (rpc_client) {
+		char name[] = "switch";
+		struct rpc_sysfs_xprt_switch *xswitch =
+			(struct rpc_sysfs_xprt_switch *)xprt_switch->xps_sysfs;
+		int ret;
+
 		clnt->cl_sysfs = rpc_client;
+		rpc_client->clnt = clnt;
+		rpc_client->xprt_switch = xprt_switch;
 		kobject_uevent(&rpc_client->kobject, KOBJ_ADD);
+		ret = sysfs_create_link_nowarn(&rpc_client->kobject,
+					       &xswitch->kobject, name);
+		if (ret)
+			pr_warn("can't create link to %s in sysfs (%d)\n",
+				name, ret);
 	}
 }
 
@@ -189,6 +204,9 @@ void rpc_sysfs_client_destroy(struct rpc_clnt *clnt)
 	struct rpc_sysfs_client *rpc_client = clnt->cl_sysfs;
 
 	if (rpc_client) {
+		char name[] = "switch";
+
+		sysfs_remove_link(&rpc_client->kobject, name);
 		kobject_uevent(&rpc_client->kobject, KOBJ_REMOVE);
 		kobject_del(&rpc_client->kobject);
 		kobject_put(&rpc_client->kobject);
diff --git a/net/sunrpc/sysfs.h b/net/sunrpc/sysfs.h
index 52ec472bd4a9..760f0582aee5 100644
--- a/net/sunrpc/sysfs.h
+++ b/net/sunrpc/sysfs.h
@@ -8,6 +8,8 @@
 struct rpc_sysfs_client {
 	struct kobject kobject;
 	struct net *net;
+	struct rpc_clnt *clnt;
+	struct rpc_xprt_switch *xprt_switch;
 };
 
 struct rpc_sysfs_xprt_switch {
@@ -20,7 +22,9 @@ struct rpc_sysfs_xprt_switch {
 int rpc_sysfs_init(void);
 void rpc_sysfs_exit(void);
 
-void rpc_sysfs_client_setup(struct rpc_clnt *clnt, struct net *net);
+void rpc_sysfs_client_setup(struct rpc_clnt *clnt,
+			    struct rpc_xprt_switch *xprt_switch,
+			    struct net *net);
 void rpc_sysfs_client_destroy(struct rpc_clnt *clnt);
 void rpc_sysfs_xprt_switch_setup(struct rpc_xprt_switch *xprt_switch,
 				 struct rpc_xprt *xprt, gfp_t gfp_flags);
-- 
2.27.0

[PATCH v7 09/12] sunrpc: add add sysfs directory per xprt under each xprt_switch

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

Add individual transport directories under each transport switch
group. For instance, for each nconnect=X connections there will be
a transport directory. Naming conventions also identifies transport
type -- xprt-<id>-<type> where type is udp, tcp, rdma, local, bc.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 include/linux/sunrpc/xprt.h |  2 ++
 net/sunrpc/sysfs.c          | 67 +++++++++++++++++++++++++++++++++++++
 net/sunrpc/sysfs.h          |  8 +++++
 net/sunrpc/xprtmultipath.c  |  4 +++
 4 files changed, 81 insertions(+)

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index a2edcc42e6c4..823663c6380a 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -183,6 +183,7 @@ enum xprt_transports {
 	XPRT_TRANSPORT_LOCAL	= 257,
 };
 
+struct rpc_sysfs_xprt;
 struct rpc_xprt {
 	struct kref		kref;		/* Reference count */
 	const struct rpc_xprt_ops *ops;		/* transport methods */
@@ -291,6 +292,7 @@ struct rpc_xprt {
 #endif
 	struct rcu_head		rcu;
 	const struct xprt_class	*xprt_class;
+	struct rpc_sysfs_xprt	*xprt_sysfs;
 };
 
 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index 0aa63747f496..20f75708594f 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -82,6 +82,14 @@ static void rpc_sysfs_xprt_switch_release(struct kobject *kobj)
 	kfree(xprt_switch);
 }
 
+static void rpc_sysfs_xprt_release(struct kobject *kobj)
+{
+	struct rpc_sysfs_xprt *xprt;
+
+	xprt = container_of(kobj, struct rpc_sysfs_xprt, kobject);
+	kfree(xprt);
+}
+
 static const void *rpc_sysfs_client_namespace(struct kobject *kobj)
 {
 	return container_of(kobj, struct rpc_sysfs_client, kobject)->net;
@@ -92,6 +100,12 @@ static const void *rpc_sysfs_xprt_switch_namespace(struct kobject *kobj)
 	return container_of(kobj, struct rpc_sysfs_xprt_switch, kobject)->net;
 }
 
+static const void *rpc_sysfs_xprt_namespace(struct kobject *kobj)
+{
+	return container_of(kobj, struct rpc_sysfs_xprt,
+			    kobject)->xprt->xprt_net;
+}
+
 static struct kobj_type rpc_sysfs_client_type = {
 	.release = rpc_sysfs_client_release,
 	.sysfs_ops = &kobj_sysfs_ops,
@@ -104,6 +118,12 @@ static struct kobj_type rpc_sysfs_xprt_switch_type = {
 	.namespace = rpc_sysfs_xprt_switch_namespace,
 };
 
+static struct kobj_type rpc_sysfs_xprt_type = {
+	.release = rpc_sysfs_xprt_release,
+	.sysfs_ops = &kobj_sysfs_ops,
+	.namespace = rpc_sysfs_xprt_namespace,
+};
+
 void rpc_sysfs_exit(void)
 {
 	kobject_put(rpc_sunrpc_client_kobj);
@@ -151,6 +171,25 @@ rpc_sysfs_xprt_switch_alloc(struct kobject *parent,
 	return NULL;
 }
 
+static struct rpc_sysfs_xprt *rpc_sysfs_xprt_alloc(struct kobject *parent,
+						   struct rpc_xprt *xprt,
+						   gfp_t gfp_flags)
+{
+	struct rpc_sysfs_xprt *p;
+
+	p = kzalloc(sizeof(*p), gfp_flags);
+	if (!p)
+		goto out;
+	p->kobject.kset = rpc_sunrpc_kset;
+	if (kobject_init_and_add(&p->kobject, &rpc_sysfs_xprt_type,
+				 parent, "xprt-%d-%s", xprt->id,
+				 xprt->address_strings[RPC_DISPLAY_PROTO]) == 0)
+		return p;
+	kobject_put(&p->kobject);
+out:
+	return NULL;
+}
+
 void rpc_sysfs_client_setup(struct rpc_clnt *clnt,
 			    struct rpc_xprt_switch *xprt_switch,
 			    struct net *net)
@@ -199,6 +238,22 @@ void rpc_sysfs_xprt_switch_setup(struct rpc_xprt_switch *xprt_switch,
 	}
 }
 
+void rpc_sysfs_xprt_setup(struct rpc_xprt_switch *xprt_switch,
+			  struct rpc_xprt *xprt,
+			  gfp_t gfp_flags)
+{
+	struct rpc_sysfs_xprt *rpc_xprt;
+	struct rpc_sysfs_xprt_switch *switch_obj =
+		(struct rpc_sysfs_xprt_switch *)xprt_switch->xps_sysfs;
+
+	rpc_xprt = rpc_sysfs_xprt_alloc(&switch_obj->kobject, xprt, gfp_flags);
+	if (rpc_xprt) {
+		xprt->xprt_sysfs = rpc_xprt;
+		rpc_xprt->xprt = xprt;
+		kobject_uevent(&rpc_xprt->kobject, KOBJ_ADD);
+	}
+}
+
 void rpc_sysfs_client_destroy(struct rpc_clnt *clnt)
 {
 	struct rpc_sysfs_client *rpc_client = clnt->cl_sysfs;
@@ -225,3 +280,15 @@ void rpc_sysfs_xprt_switch_destroy(struct rpc_xprt_switch *xprt_switch)
 		xprt_switch->xps_sysfs = NULL;
 	}
 }
+
+void rpc_sysfs_xprt_destroy(struct rpc_xprt *xprt)
+{
+	struct rpc_sysfs_xprt *rpc_xprt = xprt->xprt_sysfs;
+
+	if (rpc_xprt) {
+		kobject_uevent(&rpc_xprt->kobject, KOBJ_REMOVE);
+		kobject_del(&rpc_xprt->kobject);
+		kobject_put(&rpc_xprt->kobject);
+		xprt->xprt_sysfs = NULL;
+	}
+}
diff --git a/net/sunrpc/sysfs.h b/net/sunrpc/sysfs.h
index 760f0582aee5..ff10451de6fa 100644
--- a/net/sunrpc/sysfs.h
+++ b/net/sunrpc/sysfs.h
@@ -19,6 +19,11 @@ struct rpc_sysfs_xprt_switch {
 	struct rpc_xprt *xprt;
 };
 
+struct rpc_sysfs_xprt {
+	struct kobject kobject;
+	struct rpc_xprt *xprt;
+};
+
 int rpc_sysfs_init(void);
 void rpc_sysfs_exit(void);
 
@@ -29,5 +34,8 @@ void rpc_sysfs_client_destroy(struct rpc_clnt *clnt);
 void rpc_sysfs_xprt_switch_setup(struct rpc_xprt_switch *xprt_switch,
 				 struct rpc_xprt *xprt, gfp_t gfp_flags);
 void rpc_sysfs_xprt_switch_destroy(struct rpc_xprt_switch *xprt);
+void rpc_sysfs_xprt_setup(struct rpc_xprt_switch *xprt_switch,
+			  struct rpc_xprt *xprt, gfp_t gfp_flags);
+void rpc_sysfs_xprt_destroy(struct rpc_xprt *xprt);
 
 #endif
diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c
index 2d73a35df9ee..e7973c1ff70c 100644
--- a/net/sunrpc/xprtmultipath.c
+++ b/net/sunrpc/xprtmultipath.c
@@ -57,6 +57,7 @@ void rpc_xprt_switch_add_xprt(struct rpc_xprt_switch *xps,
 	if (xps->xps_net == xprt->xprt_net || xps->xps_net == NULL)
 		xprt_switch_add_xprt_locked(xps, xprt);
 	spin_unlock(&xps->xps_lock);
+	rpc_sysfs_xprt_setup(xps, xprt, GFP_KERNEL);
 }
 
 static void xprt_switch_remove_xprt_locked(struct rpc_xprt_switch *xps,
@@ -85,6 +86,7 @@ void rpc_xprt_switch_remove_xprt(struct rpc_xprt_switch *xps,
 	spin_lock(&xps->xps_lock);
 	xprt_switch_remove_xprt_locked(xps, xprt);
 	spin_unlock(&xps->xps_lock);
+	rpc_sysfs_xprt_destroy(xprt);
 	xprt_put(xprt);
 }
 
@@ -137,6 +139,7 @@ struct rpc_xprt_switch *xprt_switch_alloc(struct rpc_xprt *xprt,
 		xps->xps_iter_ops = &rpc_xprt_iter_singular;
 		rpc_sysfs_xprt_switch_setup(xps, xprt, gfp_flags);
 		xprt_switch_add_xprt_locked(xps, xprt);
+		rpc_sysfs_xprt_setup(xps, xprt, gfp_flags);
 	}
 
 	return xps;
@@ -152,6 +155,7 @@ static void xprt_switch_free_entries(struct rpc_xprt_switch *xps)
 				struct rpc_xprt, xprt_switch);
 		xprt_switch_remove_xprt_locked(xps, xprt);
 		spin_unlock(&xps->xps_lock);
+		rpc_sysfs_xprt_destroy(xprt);
 		xprt_put(xprt);
 		spin_lock(&xps->xps_lock);
 	}
-- 
2.27.0

[PATCH v7 10/12] sunrpc: add dst_attr attributes to the sysfs xprt directory

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

Allow to query and set the destination's address of a transport.
Setting of the destination address is allowed only for TCP or RDMA
based connections.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 include/linux/sunrpc/xprt.h |   1 +
 net/sunrpc/sysfs.c          | 100 ++++++++++++++++++++++++++++++++++++
 net/sunrpc/xprt.c           |   2 +-
 3 files changed, 102 insertions(+), 1 deletion(-)

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 823663c6380a..579c42901fc8 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -412,6 +412,7 @@ void			xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 
 bool			xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
 void			xprt_unlock_connect(struct rpc_xprt *, void *);
+void			xprt_release_write(struct rpc_xprt *, struct rpc_task *);
 
 /*
  * Reserved bit positions in xprt->state
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index 20f75708594f..f330148433c8 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -4,8 +4,24 @@
  */
 #include <linux/sunrpc/clnt.h>
 #include <linux/kobject.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/xprtsock.h>
+
 #include "sysfs.h"
 
+struct xprt_addr {
+	const char *addr;
+	struct rcu_head rcu;
+};
+
+static void free_xprt_addr(struct rcu_head *head)
+{
+	struct xprt_addr *addr = container_of(head, struct xprt_addr, rcu);
+
+	kfree(addr->addr);
+	kfree(addr);
+}
+
 static struct kset *rpc_sunrpc_kset;
 static struct kobject *rpc_sunrpc_client_kobj, *rpc_sunrpc_xprt_switch_kobj;
 
@@ -43,6 +59,81 @@ static struct kobject *rpc_sysfs_object_alloc(const char *name,
 	return NULL;
 }
 
+static inline struct rpc_xprt *
+rpc_sysfs_xprt_kobj_get_xprt(struct kobject *kobj)
+{
+	struct rpc_sysfs_xprt *x = container_of(kobj,
+		struct rpc_sysfs_xprt, kobject);
+
+	return xprt_get(x->xprt);
+}
+
+static ssize_t rpc_sysfs_xprt_dstaddr_show(struct kobject *kobj,
+					   struct kobj_attribute *attr,
+					   char *buf)
+{
+	struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj);
+	ssize_t ret;
+
+	if (!xprt)
+		return 0;
+	ret = sprintf(buf, "%s\n", xprt->address_strings[RPC_DISPLAY_ADDR]);
+	xprt_put(xprt);
+	return ret + 1;
+}
+
+static ssize_t rpc_sysfs_xprt_dstaddr_store(struct kobject *kobj,
+					    struct kobj_attribute *attr,
+					    const char *buf, size_t count)
+{
+	struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj);
+	struct sockaddr *saddr;
+	char *dst_addr;
+	int port;
+	struct xprt_addr *saved_addr;
+
+	if (!xprt)
+		return 0;
+	if (!(xprt->xprt_class->ident == XPRT_TRANSPORT_TCP ||
+	      xprt->xprt_class->ident == XPRT_TRANSPORT_RDMA)) {
+		xprt_put(xprt);
+		return -EOPNOTSUPP;
+	}
+
+	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE)) {
+		count = -EINTR;
+		goto out_put;
+	}
+	saddr = (struct sockaddr *)&xprt->addr;
+	port = rpc_get_port(saddr);
+
+	dst_addr = kstrndup(buf, count - 1, GFP_KERNEL);
+	if (!dst_addr)
+		goto out_err;
+	saved_addr = kzalloc(sizeof(*saved_addr), GFP_KERNEL);
+	if (!saved_addr)
+		goto out_err_free;
+	saved_addr->addr =
+		rcu_dereference_raw(xprt->address_strings[RPC_DISPLAY_ADDR]);
+	rcu_assign_pointer(xprt->address_strings[RPC_DISPLAY_ADDR], dst_addr);
+	call_rcu(&saved_addr->rcu, free_xprt_addr);
+	xprt->addrlen = rpc_pton(xprt->xprt_net, buf, count - 1, saddr,
+				 sizeof(*saddr));
+	rpc_set_port(saddr, port);
+
+	xprt_force_disconnect(xprt);
+out:
+	xprt_release_write(xprt, NULL);
+out_put:
+	xprt_put(xprt);
+	return count;
+out_err_free:
+	kfree(dst_addr);
+out_err:
+	count = -ENOMEM;
+	goto out;
+}
+
 int rpc_sysfs_init(void)
 {
 	rpc_sunrpc_kset = kset_create_and_add("sunrpc", NULL, kernel_kobj);
@@ -106,6 +197,14 @@ static const void *rpc_sysfs_xprt_namespace(struct kobject *kobj)
 			    kobject)->xprt->xprt_net;
 }
 
+static struct kobj_attribute rpc_sysfs_xprt_dstaddr = __ATTR(dstaddr,
+	0644, rpc_sysfs_xprt_dstaddr_show, rpc_sysfs_xprt_dstaddr_store);
+
+static struct attribute *rpc_sysfs_xprt_attrs[] = {
+	&rpc_sysfs_xprt_dstaddr.attr,
+	NULL,
+};
+
 static struct kobj_type rpc_sysfs_client_type = {
 	.release = rpc_sysfs_client_release,
 	.sysfs_ops = &kobj_sysfs_ops,
@@ -120,6 +219,7 @@ static struct kobj_type rpc_sysfs_xprt_switch_type = {
 
 static struct kobj_type rpc_sysfs_xprt_type = {
 	.release = rpc_sysfs_xprt_release,
+	.default_attrs = rpc_sysfs_xprt_attrs,
 	.sysfs_ops = &kobj_sysfs_ops,
 	.namespace = rpc_sysfs_xprt_namespace,
 };
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index fd58a3a16add..b9beb7fc453d 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -442,7 +442,7 @@ void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
 }
 EXPORT_SYMBOL_GPL(xprt_release_xprt_cong);
 
-static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
+void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
 {
 	if (xprt->snd_task != task)
 		return;
-- 
2.27.0

[PATCH v7 11/12] sunrpc: provide transport info in the sysfs directory

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

Allow to query transport's attributes. Currently showing following
fields of the rpc_xprt structure: state, last_used, cong, cwnd,
max_reqs, min_reqs, num_reqs, sizes of queues binding, sending,
pending, backlog.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 net/sunrpc/sysfs.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index f330148433c8..f1936effa5a0 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -82,6 +82,55 @@ static ssize_t rpc_sysfs_xprt_dstaddr_show(struct kobject *kobj,
 	return ret + 1;
 }
 
+static ssize_t rpc_sysfs_xprt_info_show(struct kobject *kobj,
+					struct kobj_attribute *attr,
+					char *buf)
+{
+	struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj);
+	ssize_t ret;
+	int locked, connected, connecting, close_wait, bound, binding,
+	    closing, congested, cwnd_wait, write_space;
+
+	if (!xprt)
+		return 0;
+
+	if (!xprt->state) {
+		ret = sprintf(buf, "state=CLOSED\n");
+	} else {
+		locked = test_bit(XPRT_LOCKED, &xprt->state);
+		connected = test_bit(XPRT_CONNECTED, &xprt->state);
+		connecting = test_bit(XPRT_CONNECTING, &xprt->state);
+		close_wait = test_bit(XPRT_CLOSE_WAIT, &xprt->state);
+		bound = test_bit(XPRT_BOUND, &xprt->state);
+		binding = test_bit(XPRT_BINDING, &xprt->state);
+		closing = test_bit(XPRT_CLOSING, &xprt->state);
+		congested = test_bit(XPRT_CONGESTED, &xprt->state);
+		cwnd_wait = test_bit(XPRT_CWND_WAIT, &xprt->state);
+		write_space = test_bit(XPRT_WRITE_SPACE, &xprt->state);
+
+		ret = sprintf(buf, "state=%s %s %s %s %s %s %s %s %s %s\n",
+			      locked ? "LOCKED" : "",
+			      connected ? "CONNECTED" : "",
+			      connecting ? "CONNECTING" : "",
+			      close_wait ? "CLOSE_WAIT" : "",
+			      bound ? "BOUND" : "",
+			      binding ? "BOUNDING" : "",
+			      closing ? "CLOSING" : "",
+			      congested ? "CONGESTED" : "",
+			      cwnd_wait ? "CWND_WAIT" : "",
+			      write_space ? "WRITE_SPACE" : "");
+	}
+	ret += sprintf(buf + ret, "last_used=%lu\ncur_cong=%lu\ncong_win=%lu\n"
+		       "max_num_slots=%u\nmin_num_slots=%u\nnum_reqs=%u\n"
+		       "binding_q_len=%u\nsending_q_len=%u\npending_q_len=%u\n"
+		       "backlog_q_len=%u\n", xprt->last_used, xprt->cong,
+		       xprt->cwnd, xprt->max_reqs, xprt->min_reqs,
+		       xprt->num_reqs, xprt->binding.qlen, xprt->sending.qlen,
+		       xprt->pending.qlen, xprt->backlog.qlen);
+	xprt_put(xprt);
+	return ret + 1;
+}
+
 static ssize_t rpc_sysfs_xprt_dstaddr_store(struct kobject *kobj,
 					    struct kobj_attribute *attr,
 					    const char *buf, size_t count)
@@ -200,8 +249,12 @@ static const void *rpc_sysfs_xprt_namespace(struct kobject *kobj)
 static struct kobj_attribute rpc_sysfs_xprt_dstaddr = __ATTR(dstaddr,
 	0644, rpc_sysfs_xprt_dstaddr_show, rpc_sysfs_xprt_dstaddr_store);
 
+static struct kobj_attribute rpc_sysfs_xprt_info = __ATTR(xprt_info,
+	0444, rpc_sysfs_xprt_info_show, NULL);
+
 static struct attribute *rpc_sysfs_xprt_attrs[] = {
 	&rpc_sysfs_xprt_dstaddr.attr,
+	&rpc_sysfs_xprt_info.attr,
 	NULL,
 };
 
-- 
2.27.0

[PATCH v7 12/12] sunrpc: provide multipath info in the sysfs directory

[Olga Kornievskaia]

From: Olga Kornievskaia <kolga@netapp.com>

Allow to query xrpt_switch attributes. Currently showing the following
fields of the rpc_xprt_switch structure: xps_nxprts, xps_nactive,
xps_queuelen.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 net/sunrpc/sysfs.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index f1936effa5a0..6da86bdad844 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -68,6 +68,15 @@ rpc_sysfs_xprt_kobj_get_xprt(struct kobject *kobj)
 	return xprt_get(x->xprt);
 }
 
+static inline struct rpc_xprt_switch *
+rpc_sysfs_xprt_switch_kobj_get_xprt(struct kobject *kobj)
+{
+	struct rpc_sysfs_xprt_switch *x = container_of(kobj,
+		struct rpc_sysfs_xprt_switch, kobject);
+
+	return xprt_switch_get(x->xprt_switch);
+}
+
 static ssize_t rpc_sysfs_xprt_dstaddr_show(struct kobject *kobj,
 					   struct kobj_attribute *attr,
 					   char *buf)
@@ -131,6 +140,23 @@ static ssize_t rpc_sysfs_xprt_info_show(struct kobject *kobj,
 	return ret + 1;
 }
 
+static ssize_t rpc_sysfs_xprt_switch_info_show(struct kobject *kobj,
+					       struct kobj_attribute *attr,
+					       char *buf)
+{
+	struct rpc_xprt_switch *xprt_switch =
+		rpc_sysfs_xprt_switch_kobj_get_xprt(kobj);
+	ssize_t ret;
+
+	if (!xprt_switch)
+		return 0;
+	ret = sprintf(buf, "num_xprts=%u\nnum_active=%u\nqueue_len=%ld\n",
+		      xprt_switch->xps_nxprts, xprt_switch->xps_nactive,
+		      atomic_long_read(&xprt_switch->xps_queuelen));
+	xprt_switch_put(xprt_switch);
+	return ret + 1;
+}
+
 static ssize_t rpc_sysfs_xprt_dstaddr_store(struct kobject *kobj,
 					    struct kobj_attribute *attr,
 					    const char *buf, size_t count)
@@ -258,6 +284,14 @@ static struct attribute *rpc_sysfs_xprt_attrs[] = {
 	NULL,
 };
 
+static struct kobj_attribute rpc_sysfs_xprt_switch_info =
+	__ATTR(xprt_switch_info, 0444, rpc_sysfs_xprt_switch_info_show, NULL);
+
+static struct attribute *rpc_sysfs_xprt_switch_attrs[] = {
+	&rpc_sysfs_xprt_switch_info.attr,
+	NULL,
+};
+
 static struct kobj_type rpc_sysfs_client_type = {
 	.release = rpc_sysfs_client_release,
 	.sysfs_ops = &kobj_sysfs_ops,
@@ -266,6 +300,7 @@ static struct kobj_type rpc_sysfs_client_type = {
 
 static struct kobj_type rpc_sysfs_xprt_switch_type = {
 	.release = rpc_sysfs_xprt_switch_release,
+	.default_attrs = rpc_sysfs_xprt_switch_attrs,
 	.sysfs_ops = &kobj_sysfs_ops,
 	.namespace = rpc_sysfs_xprt_switch_namespace,
 };
-- 
2.27.0

Re: [PATCH v7 10/12] sunrpc: add dst_attr attributes to the sysfs xprt directory

[Dan Aloni]

On Fri, May 14, 2021 at 10:13:21AM -0400, Olga Kornievskaia wrote:
> From: Olga Kornievskaia <kolga@netapp.com>
> 
> Allow to query and set the destination's address of a transport.
> Setting of the destination address is allowed only for TCP or RDMA
> based connections.
> 
> Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
..
> +	saddr = (struct sockaddr *)&xprt->addr;
> +	port = rpc_get_port(saddr);
> +
> +	dst_addr = kstrndup(buf, count - 1, GFP_KERNEL);
> +	if (!dst_addr)
> +		goto out_err;
> +	saved_addr = kzalloc(sizeof(*saved_addr), GFP_KERNEL);
> +	if (!saved_addr)
> +		goto out_err_free;
> +	saved_addr->addr =
> +		rcu_dereference_raw(xprt->address_strings[RPC_DISPLAY_ADDR]);
> +	rcu_assign_pointer(xprt->address_strings[RPC_DISPLAY_ADDR], dst_addr);
> +	call_rcu(&saved_addr->rcu, free_xprt_addr);
> +	xprt->addrlen = rpc_pton(xprt->xprt_net, buf, count - 1, saddr,
> +				 sizeof(*saddr));

Hi Olga,

How does this behave if rpc_pton fails? Perhaps this conversion being
also a validation check on input given from user-space should be done
before the xprt is being modified?

-- 
Dan Aloni

Re: [PATCH v7 10/12] sunrpc: add dst_attr attributes to the sysfs xprt directory

[Olga Kornievskaia]

On Sat, May 15, 2021 at 8:42 AM Dan Aloni <dan@kernelim.com> wrote:
>
> On Fri, May 14, 2021 at 10:13:21AM -0400, Olga Kornievskaia wrote:
> > From: Olga Kornievskaia <kolga@netapp.com>
> >
> > Allow to query and set the destination's address of a transport.
> > Setting of the destination address is allowed only for TCP or RDMA
> > based connections.
> >
> > Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
> ..
> > +     saddr = (struct sockaddr *)&xprt->addr;
> > +     port = rpc_get_port(saddr);
> > +
> > +     dst_addr = kstrndup(buf, count - 1, GFP_KERNEL);
> > +     if (!dst_addr)
> > +             goto out_err;
> > +     saved_addr = kzalloc(sizeof(*saved_addr), GFP_KERNEL);
> > +     if (!saved_addr)
> > +             goto out_err_free;
> > +     saved_addr->addr =
> > +             rcu_dereference_raw(xprt->address_strings[RPC_DISPLAY_ADDR]);
> > +     rcu_assign_pointer(xprt->address_strings[RPC_DISPLAY_ADDR], dst_addr);
> > +     call_rcu(&saved_addr->rcu, free_xprt_addr);
> > +     xprt->addrlen = rpc_pton(xprt->xprt_net, buf, count - 1, saddr,
> > +                              sizeof(*saddr));
>
> Hi Olga,
>
> How does this behave if rpc_pton fails? Perhaps this conversion being
> also a validation check on input given from user-space should be done
> before the xprt is being modified?

It's assumed that an administrator is providing a valid (and correct)
address value. Transport would continue to be disconnected until a
proper value is supplied. We can't validate for instance that the
supplied value is a "correct" value for the v4.1 server (which would
require sending an EXCHANGE_ID and checking that it's the same server
as before).

But yes perhaps a userland utility can do things like DNS resolution
to get the IP, it can check format correctness and connectivity as
well (but can't check the v4 requirement though).

>
> --
> Dan Aloni

Re: [PATCH v7 10/12] sunrpc: add dst_attr attributes to the sysfs xprt directory

[Dan Aloni]

On Mon, May 17, 2021 at 09:53:30AM -0400, Olga Kornievskaia wrote:
> On Sat, May 15, 2021 at 8:42 AM Dan Aloni <dan@kernelim.com> wrote:
> >
> > On Fri, May 14, 2021 at 10:13:21AM -0400, Olga Kornievskaia wrote:
> > > From: Olga Kornievskaia <kolga@netapp.com>
> > >
> > > Allow to query and set the destination's address of a transport.
> > > Setting of the destination address is allowed only for TCP or RDMA
> > > based connections.
> > >
> > > Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
> > ..
> > > +     saddr = (struct sockaddr *)&xprt->addr;
> > > +     port = rpc_get_port(saddr);
> > > +
> > > +     dst_addr = kstrndup(buf, count - 1, GFP_KERNEL);
> > > +     if (!dst_addr)
> > > +             goto out_err;
> > > +     saved_addr = kzalloc(sizeof(*saved_addr), GFP_KERNEL);
> > > +     if (!saved_addr)
> > > +             goto out_err_free;
> > > +     saved_addr->addr =
> > > +             rcu_dereference_raw(xprt->address_strings[RPC_DISPLAY_ADDR]);
> > > +     rcu_assign_pointer(xprt->address_strings[RPC_DISPLAY_ADDR], dst_addr);
> > > +     call_rcu(&saved_addr->rcu, free_xprt_addr);
> > > +     xprt->addrlen = rpc_pton(xprt->xprt_net, buf, count - 1, saddr,
> > > +                              sizeof(*saddr));
> >
> > Hi Olga,
> >
> > How does this behave if rpc_pton fails? Perhaps this conversion being
> > also a validation check on input given from user-space should be done
> > before the xprt is being modified?
> 
> It's assumed that an administrator is providing a valid (and correct)
> address value. Transport would continue to be disconnected until a
> proper value is supplied. We can't validate for instance that the
> supplied value is a "correct" value for the v4.1 server (which would
> require sending an EXCHANGE_ID and checking that it's the same server
> as before).

I'm not sure it would work that way - looks like `rpc_pton` zeroes
`saddr` before trying to fill it (or leaves it as it in other cases such
as the INET_ADDRSTRLEN bound check). I think `0.0.0.0` routes to
localhost by default? That might cause unexpected behavior from admin PoV.

More to consider is that `xprt->address_strings[RPC_DISPLAY_ADDR]`
should be consistent with the value of `saddr` in the error cases,
otherwise debugging xprt state may be give confusing output.

-- 
Dan Aloni

Re: [PATCH v7 10/12] sunrpc: add dst_attr attributes to the sysfs xprt directory

[Olga Kornievskaia]

On Mon, May 17, 2021 at 1:16 PM Dan Aloni <dan@kernelim.com> wrote:
>
> On Mon, May 17, 2021 at 09:53:30AM -0400, Olga Kornievskaia wrote:
> > On Sat, May 15, 2021 at 8:42 AM Dan Aloni <dan@kernelim.com> wrote:
> > >
> > > On Fri, May 14, 2021 at 10:13:21AM -0400, Olga Kornievskaia wrote:
> > > > From: Olga Kornievskaia <kolga@netapp.com>
> > > >
> > > > Allow to query and set the destination's address of a transport.
> > > > Setting of the destination address is allowed only for TCP or RDMA
> > > > based connections.
> > > >
> > > > Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
> > > ..
> > > > +     saddr = (struct sockaddr *)&xprt->addr;
> > > > +     port = rpc_get_port(saddr);
> > > > +
> > > > +     dst_addr = kstrndup(buf, count - 1, GFP_KERNEL);
> > > > +     if (!dst_addr)
> > > > +             goto out_err;
> > > > +     saved_addr = kzalloc(sizeof(*saved_addr), GFP_KERNEL);
> > > > +     if (!saved_addr)
> > > > +             goto out_err_free;
> > > > +     saved_addr->addr =
> > > > +             rcu_dereference_raw(xprt->address_strings[RPC_DISPLAY_ADDR]);
> > > > +     rcu_assign_pointer(xprt->address_strings[RPC_DISPLAY_ADDR], dst_addr);
> > > > +     call_rcu(&saved_addr->rcu, free_xprt_addr);
> > > > +     xprt->addrlen = rpc_pton(xprt->xprt_net, buf, count - 1, saddr,
> > > > +                              sizeof(*saddr));
> > >
> > > Hi Olga,
> > >
> > > How does this behave if rpc_pton fails? Perhaps this conversion being
> > > also a validation check on input given from user-space should be done
> > > before the xprt is being modified?
> >
> > It's assumed that an administrator is providing a valid (and correct)
> > address value. Transport would continue to be disconnected until a
> > proper value is supplied. We can't validate for instance that the
> > supplied value is a "correct" value for the v4.1 server (which would
> > require sending an EXCHANGE_ID and checking that it's the same server
> > as before).
>
> I'm not sure it would work that way - looks like `rpc_pton` zeroes
> `saddr` before trying to fill it (or leaves it as it in other cases such
> as the INET_ADDRSTRLEN bound check). I think `0.0.0.0` routes to
> localhost by default? That might cause unexpected behavior from admin PoV.
>
> More to consider is that `xprt->address_strings[RPC_DISPLAY_ADDR]`
> should be consistent with the value of `saddr` in the error cases,
> otherwise debugging xprt state may be give confusing output.

the reason for rpc_pton() to fail if an incorrect address is supplied.
I again said that given that this is a privileged operation, we rely
on the admin to provide a correct address. But are you arguing for
checking return or rpt_pton() and then reverting address_string
assignment back to the saved value and returning? Ok, I can do that.
But what can't be done is that once xprt_force_disconnect() is called
(1) we can't know if re-connect to the newly provided value is
successful and (2) thus we can't roll back the address values to the
old ones. Seems the added complexity is not gaining us much in return.
As I said I think the userspace tool that would sit on top of this
would do all the checks first before using the sysfs.

>
> --
> Dan Aloni