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* [PATCH net-next 0/4] afs: Refcount afs_call struct
@ 2017-01-09 14:52 David Howells
  2017-01-09 14:52 ` [PATCH net-next 1/4] afs: Add some tracepoints David Howells
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: David Howells @ 2017-01-09 14:52 UTC (permalink / raw)
  To: netdev; +Cc: dhowells, linux-afs, linux-kernel


These patches provide some tracepoints for AFS and fix a potential leak by
adding refcounting to the afs_call struct.

The patches are:

 (1) Add some tracepoints for logging incoming calls and monitoring
     notifications from AF_RXRPC and data reception.

 (2) Get rid of afs_wait_mode as it didn't turn out to be as useful as
     initially expected.  It can be brought back later if needed.  This
     clears some stuff out that I don't then need to fix up in (4).

 (3) Allow listen(..., 0) to be used to disable listening.  This makes
     shutting down the AFS cache manager server in the kernel much easier
     and the accounting simpler as we can then be sure that (a) all
     preallocated afs_call structs are relesed and (b) no new incoming
     calls are going to be started.

     For the moment, listening cannot be reenabled.

 (4) Add refcounting to the afs_call struct to fix a potential multiple
     release detected by static checking and add a tracepoint to follow the
     lifecycle of afs_call objects.

The patches can be found here also:

	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-rewrite

Tagged thusly:

	git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git
	rxrpc-rewrite-20170109

David
---
David Howells (4):
      afs: Add some tracepoints
      afs: Kill afs_wait_mode
      rxrpc: Allow listen(sock, 0) to be used to disable listening
      afs: Refcount the afs_call struct


 fs/afs/callback.c          |    2 
 fs/afs/cmservice.c         |   63 ++++++++-----
 fs/afs/fsclient.c          |   80 ++++++++---------
 fs/afs/internal.h          |   96 ++++++++------------
 fs/afs/main.c              |    1 
 fs/afs/rxrpc.c             |  208 +++++++++++++++++++++++---------------------
 fs/afs/vlclient.c          |    8 +-
 fs/afs/vlocation.c         |    4 -
 fs/afs/vnode.c             |   26 +++---
 include/trace/events/afs.h |  184 +++++++++++++++++++++++++++++++++++++++
 net/rxrpc/af_rxrpc.c       |    8 ++
 net/rxrpc/ar-internal.h    |    1 
 net/rxrpc/call_accept.c    |    3 -
 13 files changed, 442 insertions(+), 242 deletions(-)
 create mode 100644 include/trace/events/afs.h

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH net-next 1/4] afs: Add some tracepoints
  2017-01-09 14:52 [PATCH net-next 0/4] afs: Refcount afs_call struct David Howells
@ 2017-01-09 14:52 ` David Howells
  2017-01-09 14:53 ` [PATCH net-next 2/4] afs: Kill afs_wait_mode David Howells
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: David Howells @ 2017-01-09 14:52 UTC (permalink / raw)
  To: netdev; +Cc: dhowells, linux-afs, linux-kernel

Add three tracepoints to the AFS filesystem:

 (1) The afs_recv_data tracepoint logs data segments that are extracted
     from the data received from the peer through afs_extract_data().

 (2) The afs_notify_call tracepoint logs notification from AF_RXRPC of data
     coming in to an asynchronous call.

 (3) The afs_cb_call tracepoint logs incoming calls that have had their
     operation ID extracted and mapped into a supported cache manager
     service call.

To make (3) work, the name strings in the afs_call_type struct objects have
to be annotated with __tracepoint_string.  This is done with the CM_NAME()
macro.

Further, the AFS call state enum needs a name so that it can be used to
declare parameter types.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/cmservice.c         |   22 ++++++---
 fs/afs/internal.h          |   21 +++++---
 fs/afs/main.c              |    1 
 fs/afs/rxrpc.c             |    6 ++
 include/trace/events/afs.h |  109 ++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 144 insertions(+), 15 deletions(-)
 create mode 100644 include/trace/events/afs.h

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index d764236072b1..a2e1e02005f6 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -25,11 +25,16 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *);
 static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *);
 static void afs_cm_destructor(struct afs_call *);
 
+#define CM_NAME(name) \
+	const char afs_SRXCB##name##_name[] __tracepoint_string =	\
+		"CB." #name
+
 /*
  * CB.CallBack operation type
  */
+static CM_NAME(CallBack);
 static const struct afs_call_type afs_SRXCBCallBack = {
-	.name		= "CB.CallBack",
+	.name		= afs_SRXCBCallBack_name,
 	.deliver	= afs_deliver_cb_callback,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
@@ -38,8 +43,9 @@ static const struct afs_call_type afs_SRXCBCallBack = {
 /*
  * CB.InitCallBackState operation type
  */
+static CM_NAME(InitCallBackState);
 static const struct afs_call_type afs_SRXCBInitCallBackState = {
-	.name		= "CB.InitCallBackState",
+	.name		= afs_SRXCBInitCallBackState_name,
 	.deliver	= afs_deliver_cb_init_call_back_state,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
@@ -48,8 +54,9 @@ static const struct afs_call_type afs_SRXCBInitCallBackState = {
 /*
  * CB.InitCallBackState3 operation type
  */
+static CM_NAME(InitCallBackState3);
 static const struct afs_call_type afs_SRXCBInitCallBackState3 = {
-	.name		= "CB.InitCallBackState3",
+	.name		= afs_SRXCBInitCallBackState3_name,
 	.deliver	= afs_deliver_cb_init_call_back_state3,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
@@ -58,8 +65,9 @@ static const struct afs_call_type afs_SRXCBInitCallBackState3 = {
 /*
  * CB.Probe operation type
  */
+static CM_NAME(Probe);
 static const struct afs_call_type afs_SRXCBProbe = {
-	.name		= "CB.Probe",
+	.name		= afs_SRXCBProbe_name,
 	.deliver	= afs_deliver_cb_probe,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
@@ -68,8 +76,9 @@ static const struct afs_call_type afs_SRXCBProbe = {
 /*
  * CB.ProbeUuid operation type
  */
+static CM_NAME(ProbeUuid);
 static const struct afs_call_type afs_SRXCBProbeUuid = {
-	.name		= "CB.ProbeUuid",
+	.name		= afs_SRXCBProbeUuid_name,
 	.deliver	= afs_deliver_cb_probe_uuid,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
@@ -78,8 +87,9 @@ static const struct afs_call_type afs_SRXCBProbeUuid = {
 /*
  * CB.TellMeAboutYourself operation type
  */
+static CM_NAME(TellMeAboutYourself);
 static const struct afs_call_type afs_SRXCBTellMeAboutYourself = {
-	.name		= "CB.TellMeAboutYourself",
+	.name		= afs_SRXCBTellMeAboutYourself_name,
 	.deliver	= afs_deliver_cb_tell_me_about_yourself,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 6f7a9638ba1a..f71e58fcc2f2 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -68,6 +68,15 @@ struct afs_wait_mode {
 extern const struct afs_wait_mode afs_sync_call;
 extern const struct afs_wait_mode afs_async_call;
 
+enum afs_call_state {
+	AFS_CALL_REQUESTING,	/* request is being sent for outgoing call */
+	AFS_CALL_AWAIT_REPLY,	/* awaiting reply to outgoing call */
+	AFS_CALL_AWAIT_OP_ID,	/* awaiting op ID on incoming call */
+	AFS_CALL_AWAIT_REQUEST,	/* awaiting request data on incoming call */
+	AFS_CALL_REPLYING,	/* replying to incoming call */
+	AFS_CALL_AWAIT_ACK,	/* awaiting final ACK of incoming call */
+	AFS_CALL_COMPLETE,	/* Completed or failed */
+};
 /*
  * a record of an in-progress RxRPC call
  */
@@ -91,15 +100,7 @@ struct afs_call {
 	pgoff_t			first;		/* first page in mapping to deal with */
 	pgoff_t			last;		/* last page in mapping to deal with */
 	size_t			offset;		/* offset into received data store */
-	enum {					/* call state */
-		AFS_CALL_REQUESTING,	/* request is being sent for outgoing call */
-		AFS_CALL_AWAIT_REPLY,	/* awaiting reply to outgoing call */
-		AFS_CALL_AWAIT_OP_ID,	/* awaiting op ID on incoming call */
-		AFS_CALL_AWAIT_REQUEST,	/* awaiting request data on incoming call */
-		AFS_CALL_REPLYING,	/* replying to incoming call */
-		AFS_CALL_AWAIT_ACK,	/* awaiting final ACK of incoming call */
-		AFS_CALL_COMPLETE,	/* Completed or failed */
-	}			state;
+	enum afs_call_state	state;
 	int			error;		/* error code */
 	u32			abort_code;	/* Remote abort ID or 0 */
 	unsigned		request_size;	/* size of request data */
@@ -773,6 +774,8 @@ extern int afs_fsync(struct file *, loff_t, loff_t, int);
 /*
  * debug tracing
  */
+#include <trace/events/afs.h>
+
 extern unsigned afs_debug;
 
 #define dbgprintk(FMT,...) \
diff --git a/fs/afs/main.c b/fs/afs/main.c
index 0b187ef3b5b7..f8188feb03ad 100644
--- a/fs/afs/main.c
+++ b/fs/afs/main.c
@@ -15,6 +15,7 @@
 #include <linux/completion.h>
 #include <linux/sched.h>
 #include <linux/random.h>
+#define CREATE_TRACE_POINTS
 #include "internal.h"
 
 MODULE_DESCRIPTION("AFS Client File System");
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 25f05a8d21b1..f26344a8c029 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -416,6 +416,8 @@ static void afs_deliver_to_call(struct afs_call *call)
 			ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
 						     NULL, 0, &offset, false,
 						     &call->abort_code);
+			trace_afs_recv_data(call, 0, offset, false, ret);
+
 			if (ret == -EINPROGRESS || ret == -EAGAIN)
 				return;
 			if (ret == 1 || ret < 0) {
@@ -541,6 +543,7 @@ static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 {
 	struct afs_call *call = (struct afs_call *)call_user_ID;
 
+	trace_afs_notify_call(rxcall, call);
 	call->need_attention = true;
 	queue_work(afs_async_calls, &call->async_work);
 }
@@ -689,6 +692,8 @@ static int afs_deliver_cm_op_id(struct afs_call *call)
 	if (!afs_cm_incoming_call(call))
 		return -ENOTSUPP;
 
+	trace_afs_cb_call(call);
+
 	/* pass responsibility for the remainer of this message off to the
 	 * cache manager op */
 	return call->type->deliver(call);
@@ -780,6 +785,7 @@ int afs_extract_data(struct afs_call *call, void *buf, size_t count,
 	ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
 				     buf, count, &call->offset,
 				     want_more, &call->abort_code);
+	trace_afs_recv_data(call, count, call->offset, want_more, ret);
 	if (ret == 0 || ret == -EAGAIN)
 		return ret;
 
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
new file mode 100644
index 000000000000..845907b04ff4
--- /dev/null
+++ b/include/trace/events/afs.h
@@ -0,0 +1,109 @@
+/* AFS tracepoints
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM afs
+
+#if !defined(_TRACE_AFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_AFS_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(afs_recv_data,
+	    TP_PROTO(struct afs_call *call, unsigned count, unsigned offset,
+		     bool want_more, int ret),
+
+	    TP_ARGS(call, count, offset, want_more, ret),
+
+	    TP_STRUCT__entry(
+		    __field(struct rxrpc_call *,	rxcall		)
+		    __field(struct afs_call *,		call		)
+		    __field(enum afs_call_state,	state		)
+		    __field(unsigned int,		count		)
+		    __field(unsigned int,		offset		)
+		    __field(unsigned short,		unmarshall	)
+		    __field(bool,			want_more	)
+		    __field(int,			ret		)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->rxcall	= call->rxcall;
+		    __entry->call	= call;
+		    __entry->state	= call->state;
+		    __entry->unmarshall	= call->unmarshall;
+		    __entry->count	= count;
+		    __entry->offset	= offset;
+		    __entry->want_more	= want_more;
+		    __entry->ret	= ret;
+			   ),
+
+	    TP_printk("c=%p ac=%p s=%u u=%u %u/%u wm=%u ret=%d",
+		      __entry->rxcall,
+		      __entry->call,
+		      __entry->state, __entry->unmarshall,
+		      __entry->offset, __entry->count,
+		      __entry->want_more, __entry->ret)
+	    );
+
+TRACE_EVENT(afs_notify_call,
+	    TP_PROTO(struct rxrpc_call *rxcall, struct afs_call *call),
+
+	    TP_ARGS(rxcall, call),
+
+	    TP_STRUCT__entry(
+		    __field(struct rxrpc_call *,	rxcall		)
+		    __field(struct afs_call *,		call		)
+		    __field(enum afs_call_state,	state		)
+		    __field(unsigned short,		unmarshall	)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->rxcall	= rxcall;
+		    __entry->call	= call;
+		    __entry->state	= call->state;
+		    __entry->unmarshall	= call->unmarshall;
+			   ),
+
+	    TP_printk("c=%p ac=%p s=%u u=%u",
+		      __entry->rxcall,
+		      __entry->call,
+		      __entry->state, __entry->unmarshall)
+	    );
+
+TRACE_EVENT(afs_cb_call,
+	    TP_PROTO(struct afs_call *call),
+
+	    TP_ARGS(call),
+
+	    TP_STRUCT__entry(
+		    __field(struct rxrpc_call *,	rxcall		)
+		    __field(struct afs_call *,		call		)
+		    __field(const char *,		name		)
+		    __field(u32,			op		)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->rxcall	= call->rxcall;
+		    __entry->call	= call;
+		    __entry->name	= call->type->name;
+		    __entry->op		= call->operation_ID;
+			   ),
+
+	    TP_printk("c=%p ac=%p %s o=%u",
+		      __entry->rxcall,
+		      __entry->call,
+		      __entry->name,
+		      __entry->op)
+	    );
+
+#endif /* _TRACE_AFS_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH net-next 2/4] afs: Kill afs_wait_mode
  2017-01-09 14:52 [PATCH net-next 0/4] afs: Refcount afs_call struct David Howells
  2017-01-09 14:52 ` [PATCH net-next 1/4] afs: Add some tracepoints David Howells
@ 2017-01-09 14:53 ` David Howells
  2017-01-09 14:53 ` [PATCH net-next 3/4] rxrpc: Allow listen(sock, 0) to be used to disable listening David Howells
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: David Howells @ 2017-01-09 14:53 UTC (permalink / raw)
  To: netdev; +Cc: dhowells, linux-afs, linux-kernel

The afs_wait_mode struct isn't really necessary.  Client calls only use one
of a choice of two (synchronous or the asynchronous) and incoming calls
don't use the wait at all.  Replace with a boolean parameter.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 fs/afs/callback.c  |    2 +
 fs/afs/fsclient.c  |   80 ++++++++++++++++++++++++++--------------------------
 fs/afs/internal.h  |   68 ++++++++++++--------------------------------
 fs/afs/rxrpc.c     |   51 ++++++++-------------------------
 fs/afs/vlclient.c  |    8 +++--
 fs/afs/vlocation.c |    4 +--
 fs/afs/vnode.c     |   26 ++++++++---------
 7 files changed, 90 insertions(+), 149 deletions(-)

diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index 1e9d2f84e5b5..b29447e03ede 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -343,7 +343,7 @@ void afs_dispatch_give_up_callbacks(struct work_struct *work)
 	 *   had callbacks entirely, and the server will call us later to break
 	 *   them
 	 */
-	afs_fs_give_up_callbacks(server, &afs_async_call);
+	afs_fs_give_up_callbacks(server, true);
 }
 
 /*
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 7dc1f6fb3661..ac8e766978dc 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -275,7 +275,7 @@ int afs_fs_fetch_file_status(struct afs_server *server,
 			     struct key *key,
 			     struct afs_vnode *vnode,
 			     struct afs_volsync *volsync,
-			     const struct afs_wait_mode *wait_mode)
+			     bool async)
 {
 	struct afs_call *call;
 	__be32 *bp;
@@ -300,7 +300,7 @@ int afs_fs_fetch_file_status(struct afs_server *server,
 	bp[2] = htonl(vnode->fid.vnode);
 	bp[3] = htonl(vnode->fid.unique);
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -464,7 +464,7 @@ static int afs_fs_fetch_data64(struct afs_server *server,
 			       struct key *key,
 			       struct afs_vnode *vnode,
 			       struct afs_read *req,
-			       const struct afs_wait_mode *wait_mode)
+			       bool async)
 {
 	struct afs_call *call;
 	__be32 *bp;
@@ -495,7 +495,7 @@ static int afs_fs_fetch_data64(struct afs_server *server,
 	bp[7] = htonl(lower_32_bits(req->len));
 
 	atomic_inc(&req->usage);
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -505,7 +505,7 @@ int afs_fs_fetch_data(struct afs_server *server,
 		      struct key *key,
 		      struct afs_vnode *vnode,
 		      struct afs_read *req,
-		      const struct afs_wait_mode *wait_mode)
+		      bool async)
 {
 	struct afs_call *call;
 	__be32 *bp;
@@ -513,7 +513,7 @@ int afs_fs_fetch_data(struct afs_server *server,
 	if (upper_32_bits(req->pos) ||
 	    upper_32_bits(req->len) ||
 	    upper_32_bits(req->pos + req->len))
-		return afs_fs_fetch_data64(server, key, vnode, req, wait_mode);
+		return afs_fs_fetch_data64(server, key, vnode, req, async);
 
 	_enter("");
 
@@ -539,7 +539,7 @@ int afs_fs_fetch_data(struct afs_server *server,
 	bp[5] = htonl(lower_32_bits(req->len));
 
 	atomic_inc(&req->usage);
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -568,7 +568,7 @@ static const struct afs_call_type afs_RXFSGiveUpCallBacks = {
  * - the callbacks are held in the server->cb_break ring
  */
 int afs_fs_give_up_callbacks(struct afs_server *server,
-			     const struct afs_wait_mode *wait_mode)
+			     bool async)
 {
 	struct afs_call *call;
 	size_t ncallbacks;
@@ -622,7 +622,7 @@ int afs_fs_give_up_callbacks(struct afs_server *server,
 	ASSERT(ncallbacks > 0);
 	wake_up_nr(&server->cb_break_waitq, ncallbacks);
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -673,7 +673,7 @@ int afs_fs_create(struct afs_server *server,
 		  struct afs_fid *newfid,
 		  struct afs_file_status *newstatus,
 		  struct afs_callback *newcb,
-		  const struct afs_wait_mode *wait_mode)
+		  bool async)
 {
 	struct afs_call *call;
 	size_t namesz, reqsz, padsz;
@@ -718,7 +718,7 @@ int afs_fs_create(struct afs_server *server,
 	*bp++ = htonl(mode & S_IALLUGO); /* unix mode */
 	*bp++ = 0; /* segment size */
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -763,7 +763,7 @@ int afs_fs_remove(struct afs_server *server,
 		  struct afs_vnode *vnode,
 		  const char *name,
 		  bool isdir,
-		  const struct afs_wait_mode *wait_mode)
+		  bool async)
 {
 	struct afs_call *call;
 	size_t namesz, reqsz, padsz;
@@ -798,7 +798,7 @@ int afs_fs_remove(struct afs_server *server,
 		bp = (void *) bp + padsz;
 	}
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -844,7 +844,7 @@ int afs_fs_link(struct afs_server *server,
 		struct afs_vnode *dvnode,
 		struct afs_vnode *vnode,
 		const char *name,
-		const struct afs_wait_mode *wait_mode)
+		bool async)
 {
 	struct afs_call *call;
 	size_t namesz, reqsz, padsz;
@@ -883,7 +883,7 @@ int afs_fs_link(struct afs_server *server,
 	*bp++ = htonl(vnode->fid.vnode);
 	*bp++ = htonl(vnode->fid.unique);
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -932,7 +932,7 @@ int afs_fs_symlink(struct afs_server *server,
 		   const char *contents,
 		   struct afs_fid *newfid,
 		   struct afs_file_status *newstatus,
-		   const struct afs_wait_mode *wait_mode)
+		   bool async)
 {
 	struct afs_call *call;
 	size_t namesz, reqsz, padsz, c_namesz, c_padsz;
@@ -987,7 +987,7 @@ int afs_fs_symlink(struct afs_server *server,
 	*bp++ = htonl(S_IRWXUGO); /* unix mode */
 	*bp++ = 0; /* segment size */
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -1036,7 +1036,7 @@ int afs_fs_rename(struct afs_server *server,
 		  const char *orig_name,
 		  struct afs_vnode *new_dvnode,
 		  const char *new_name,
-		  const struct afs_wait_mode *wait_mode)
+		  bool async)
 {
 	struct afs_call *call;
 	size_t reqsz, o_namesz, o_padsz, n_namesz, n_padsz;
@@ -1090,7 +1090,7 @@ int afs_fs_rename(struct afs_server *server,
 		bp = (void *) bp + n_padsz;
 	}
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -1145,7 +1145,7 @@ static int afs_fs_store_data64(struct afs_server *server,
 			       pgoff_t first, pgoff_t last,
 			       unsigned offset, unsigned to,
 			       loff_t size, loff_t pos, loff_t i_size,
-			       const struct afs_wait_mode *wait_mode)
+			       bool async)
 {
 	struct afs_vnode *vnode = wb->vnode;
 	struct afs_call *call;
@@ -1194,7 +1194,7 @@ static int afs_fs_store_data64(struct afs_server *server,
 	*bp++ = htonl(i_size >> 32);
 	*bp++ = htonl((u32) i_size);
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -1203,7 +1203,7 @@ static int afs_fs_store_data64(struct afs_server *server,
 int afs_fs_store_data(struct afs_server *server, struct afs_writeback *wb,
 		      pgoff_t first, pgoff_t last,
 		      unsigned offset, unsigned to,
-		      const struct afs_wait_mode *wait_mode)
+		      bool async)
 {
 	struct afs_vnode *vnode = wb->vnode;
 	struct afs_call *call;
@@ -1229,7 +1229,7 @@ int afs_fs_store_data(struct afs_server *server, struct afs_writeback *wb,
 
 	if (pos >> 32 || i_size >> 32 || size >> 32 || (pos + size) >> 32)
 		return afs_fs_store_data64(server, wb, first, last, offset, to,
-					   size, pos, i_size, wait_mode);
+					   size, pos, i_size, async);
 
 	call = afs_alloc_flat_call(&afs_RXFSStoreData,
 				   (4 + 6 + 3) * 4,
@@ -1268,7 +1268,7 @@ int afs_fs_store_data(struct afs_server *server, struct afs_writeback *wb,
 	*bp++ = htonl(size);
 	*bp++ = htonl(i_size);
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -1330,7 +1330,7 @@ static const struct afs_call_type afs_RXFSStoreData64_as_Status = {
  */
 static int afs_fs_setattr_size64(struct afs_server *server, struct key *key,
 				 struct afs_vnode *vnode, struct iattr *attr,
-				 const struct afs_wait_mode *wait_mode)
+				 bool async)
 {
 	struct afs_call *call;
 	__be32 *bp;
@@ -1369,7 +1369,7 @@ static int afs_fs_setattr_size64(struct afs_server *server, struct key *key,
 	*bp++ = htonl(attr->ia_size >> 32);	/* new file length */
 	*bp++ = htonl((u32) attr->ia_size);
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -1378,7 +1378,7 @@ static int afs_fs_setattr_size64(struct afs_server *server, struct key *key,
  */
 static int afs_fs_setattr_size(struct afs_server *server, struct key *key,
 			       struct afs_vnode *vnode, struct iattr *attr,
-			       const struct afs_wait_mode *wait_mode)
+			       bool async)
 {
 	struct afs_call *call;
 	__be32 *bp;
@@ -1389,7 +1389,7 @@ static int afs_fs_setattr_size(struct afs_server *server, struct key *key,
 	ASSERT(attr->ia_valid & ATTR_SIZE);
 	if (attr->ia_size >> 32)
 		return afs_fs_setattr_size64(server, key, vnode, attr,
-					     wait_mode);
+					     async);
 
 	call = afs_alloc_flat_call(&afs_RXFSStoreData_as_Status,
 				   (4 + 6 + 3) * 4,
@@ -1417,7 +1417,7 @@ static int afs_fs_setattr_size(struct afs_server *server, struct key *key,
 	*bp++ = 0;				/* size of write */
 	*bp++ = htonl(attr->ia_size);		/* new file length */
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -1426,14 +1426,14 @@ static int afs_fs_setattr_size(struct afs_server *server, struct key *key,
  */
 int afs_fs_setattr(struct afs_server *server, struct key *key,
 		   struct afs_vnode *vnode, struct iattr *attr,
-		   const struct afs_wait_mode *wait_mode)
+		   bool async)
 {
 	struct afs_call *call;
 	__be32 *bp;
 
 	if (attr->ia_valid & ATTR_SIZE)
 		return afs_fs_setattr_size(server, key, vnode, attr,
-					   wait_mode);
+					   async);
 
 	_enter(",%x,{%x:%u},,",
 	       key_serial(key), vnode->fid.vid, vnode->fid.vnode);
@@ -1459,7 +1459,7 @@ int afs_fs_setattr(struct afs_server *server, struct key *key,
 
 	xdr_encode_AFS_StoreStatus(&bp, attr);
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -1661,7 +1661,7 @@ int afs_fs_get_volume_status(struct afs_server *server,
 			     struct key *key,
 			     struct afs_vnode *vnode,
 			     struct afs_volume_status *vs,
-			     const struct afs_wait_mode *wait_mode)
+			     bool async)
 {
 	struct afs_call *call;
 	__be32 *bp;
@@ -1691,7 +1691,7 @@ int afs_fs_get_volume_status(struct afs_server *server,
 	bp[0] = htonl(FSGETVOLUMESTATUS);
 	bp[1] = htonl(vnode->fid.vid);
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -1753,7 +1753,7 @@ int afs_fs_set_lock(struct afs_server *server,
 		    struct key *key,
 		    struct afs_vnode *vnode,
 		    afs_lock_type_t type,
-		    const struct afs_wait_mode *wait_mode)
+		    bool async)
 {
 	struct afs_call *call;
 	__be32 *bp;
@@ -1777,7 +1777,7 @@ int afs_fs_set_lock(struct afs_server *server,
 	*bp++ = htonl(vnode->fid.unique);
 	*bp++ = htonl(type);
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -1786,7 +1786,7 @@ int afs_fs_set_lock(struct afs_server *server,
 int afs_fs_extend_lock(struct afs_server *server,
 		       struct key *key,
 		       struct afs_vnode *vnode,
-		       const struct afs_wait_mode *wait_mode)
+		       bool async)
 {
 	struct afs_call *call;
 	__be32 *bp;
@@ -1809,7 +1809,7 @@ int afs_fs_extend_lock(struct afs_server *server,
 	*bp++ = htonl(vnode->fid.vnode);
 	*bp++ = htonl(vnode->fid.unique);
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
 
 /*
@@ -1818,7 +1818,7 @@ int afs_fs_extend_lock(struct afs_server *server,
 int afs_fs_release_lock(struct afs_server *server,
 			struct key *key,
 			struct afs_vnode *vnode,
-			const struct afs_wait_mode *wait_mode)
+			bool async)
 {
 	struct afs_call *call;
 	__be32 *bp;
@@ -1841,5 +1841,5 @@ int afs_fs_release_lock(struct afs_server *server,
 	*bp++ = htonl(vnode->fid.vnode);
 	*bp++ = htonl(vnode->fid.unique);
 
-	return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode);
+	return afs_make_call(&server->addr, call, GFP_NOFS, async);
 }
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index f71e58fcc2f2..b411670d5f67 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -51,23 +51,6 @@ struct afs_mount_params {
 	struct key		*key;		/* key to use for secure mounting */
 };
 
-/*
- * definition of how to wait for the completion of an operation
- */
-struct afs_wait_mode {
-	/* RxRPC received message notification */
-	rxrpc_notify_rx_t notify_rx;
-
-	/* synchronous call waiter and call dispatched notification */
-	int (*wait)(struct afs_call *call);
-
-	/* asynchronous call completion */
-	void (*async_complete)(void *reply, int error);
-};
-
-extern const struct afs_wait_mode afs_sync_call;
-extern const struct afs_wait_mode afs_async_call;
-
 enum afs_call_state {
 	AFS_CALL_REQUESTING,	/* request is being sent for outgoing call */
 	AFS_CALL_AWAIT_REPLY,	/* awaiting reply to outgoing call */
@@ -82,7 +65,6 @@ enum afs_call_state {
  */
 struct afs_call {
 	const struct afs_call_type *type;	/* type of call */
-	const struct afs_wait_mode *wait_mode;	/* completion wait mode */
 	wait_queue_head_t	waitq;		/* processes awaiting completion */
 	struct work_struct	async_work;	/* asynchronous work processor */
 	struct work_struct	work;		/* actual work processor */
@@ -111,6 +93,7 @@ struct afs_call {
 	bool			incoming;	/* T if incoming call */
 	bool			send_pages;	/* T if data from mapping should be sent */
 	bool			need_attention;	/* T if RxRPC poked us */
+	bool			async;		/* T if asynchronous */
 	u16			service_id;	/* RxRPC service ID to call */
 	__be16			port;		/* target UDP port */
 	u32			operation_ID;	/* operation ID for an incoming call */
@@ -527,50 +510,37 @@ extern int afs_flock(struct file *, int, struct file_lock *);
  */
 extern int afs_fs_fetch_file_status(struct afs_server *, struct key *,
 				    struct afs_vnode *, struct afs_volsync *,
-				    const struct afs_wait_mode *);
-extern int afs_fs_give_up_callbacks(struct afs_server *,
-				    const struct afs_wait_mode *);
+				    bool);
+extern int afs_fs_give_up_callbacks(struct afs_server *, bool);
 extern int afs_fs_fetch_data(struct afs_server *, struct key *,
-			     struct afs_vnode *, struct afs_read *,
-			     const struct afs_wait_mode *);
+			     struct afs_vnode *, struct afs_read *, bool);
 extern int afs_fs_create(struct afs_server *, struct key *,
 			 struct afs_vnode *, const char *, umode_t,
 			 struct afs_fid *, struct afs_file_status *,
-			 struct afs_callback *,
-			 const struct afs_wait_mode *);
+			 struct afs_callback *, bool);
 extern int afs_fs_remove(struct afs_server *, struct key *,
-			 struct afs_vnode *, const char *, bool,
-			 const struct afs_wait_mode *);
+			 struct afs_vnode *, const char *, bool, bool);
 extern int afs_fs_link(struct afs_server *, struct key *, struct afs_vnode *,
-		       struct afs_vnode *, const char *,
-		       const struct afs_wait_mode *);
+		       struct afs_vnode *, const char *, bool);
 extern int afs_fs_symlink(struct afs_server *, struct key *,
 			  struct afs_vnode *, const char *, const char *,
-			  struct afs_fid *, struct afs_file_status *,
-			  const struct afs_wait_mode *);
+			  struct afs_fid *, struct afs_file_status *, bool);
 extern int afs_fs_rename(struct afs_server *, struct key *,
 			 struct afs_vnode *, const char *,
-			 struct afs_vnode *, const char *,
-			 const struct afs_wait_mode *);
+			 struct afs_vnode *, const char *, bool);
 extern int afs_fs_store_data(struct afs_server *, struct afs_writeback *,
-			     pgoff_t, pgoff_t, unsigned, unsigned,
-			     const struct afs_wait_mode *);
+			     pgoff_t, pgoff_t, unsigned, unsigned, bool);
 extern int afs_fs_setattr(struct afs_server *, struct key *,
-			  struct afs_vnode *, struct iattr *,
-			  const struct afs_wait_mode *);
+			  struct afs_vnode *, struct iattr *, bool);
 extern int afs_fs_get_volume_status(struct afs_server *, struct key *,
 				    struct afs_vnode *,
-				    struct afs_volume_status *,
-				    const struct afs_wait_mode *);
+				    struct afs_volume_status *, bool);
 extern int afs_fs_set_lock(struct afs_server *, struct key *,
-			   struct afs_vnode *, afs_lock_type_t,
-			   const struct afs_wait_mode *);
+			   struct afs_vnode *, afs_lock_type_t, bool);
 extern int afs_fs_extend_lock(struct afs_server *, struct key *,
-			      struct afs_vnode *,
-			      const struct afs_wait_mode *);
+			      struct afs_vnode *, bool);
 extern int afs_fs_release_lock(struct afs_server *, struct key *,
-			       struct afs_vnode *,
-			       const struct afs_wait_mode *);
+			       struct afs_vnode *, bool);
 
 /*
  * inode.c
@@ -624,8 +594,7 @@ extern struct socket *afs_socket;
 
 extern int afs_open_socket(void);
 extern void afs_close_socket(void);
-extern int afs_make_call(struct in_addr *, struct afs_call *, gfp_t,
-			 const struct afs_wait_mode *);
+extern int afs_make_call(struct in_addr *, struct afs_call *, gfp_t, bool);
 extern struct afs_call *afs_alloc_flat_call(const struct afs_call_type *,
 					    size_t, size_t);
 extern void afs_flat_call_destructor(struct afs_call *);
@@ -681,11 +650,10 @@ extern int afs_get_MAC_address(u8 *, size_t);
  */
 extern int afs_vl_get_entry_by_name(struct in_addr *, struct key *,
 				    const char *, struct afs_cache_vlocation *,
-				    const struct afs_wait_mode *);
+				    bool);
 extern int afs_vl_get_entry_by_id(struct in_addr *, struct key *,
 				  afs_volid_t, afs_voltype_t,
-				  struct afs_cache_vlocation *,
-				  const struct afs_wait_mode *);
+				  struct afs_cache_vlocation *, bool);
 
 /*
  * vlocation.c
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index f26344a8c029..ec1e41f929d1 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -25,29 +25,11 @@ static void afs_free_call(struct afs_call *);
 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
 static int afs_wait_for_call_to_complete(struct afs_call *);
 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
-static int afs_dont_wait_for_call_to_complete(struct afs_call *);
 static void afs_process_async_call(struct work_struct *);
 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
 static int afs_deliver_cm_op_id(struct afs_call *);
 
-/* synchronous call management */
-const struct afs_wait_mode afs_sync_call = {
-	.notify_rx	= afs_wake_up_call_waiter,
-	.wait		= afs_wait_for_call_to_complete,
-};
-
-/* asynchronous call management */
-const struct afs_wait_mode afs_async_call = {
-	.notify_rx	= afs_wake_up_async_call,
-	.wait		= afs_dont_wait_for_call_to_complete,
-};
-
-/* asynchronous incoming call management */
-static const struct afs_wait_mode afs_async_incoming_call = {
-	.notify_rx	= afs_wake_up_async_call,
-};
-
 /* asynchronous incoming call initial processing */
 static const struct afs_call_type afs_RXCMxxxx = {
 	.name		= "CB.xxxx",
@@ -315,7 +297,7 @@ static int afs_send_pages(struct afs_call *call, struct msghdr *msg,
  * initiate a call
  */
 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
-		  const struct afs_wait_mode *wait_mode)
+		  bool async)
 {
 	struct sockaddr_rxrpc srx;
 	struct rxrpc_call *rxcall;
@@ -332,7 +314,7 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
 	       call, call->type->name, key_serial(call->key),
 	       atomic_read(&afs_outstanding_calls));
 
-	call->wait_mode = wait_mode;
+	call->async = async;
 	INIT_WORK(&call->async_work, afs_process_async_call);
 
 	memset(&srx, 0, sizeof(srx));
@@ -347,7 +329,9 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
 	/* create a call */
 	rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
 					 (unsigned long) call, gfp,
-					 wait_mode->notify_rx);
+					 (async ?
+					  afs_wake_up_async_call :
+					  afs_wake_up_call_waiter));
 	call->key = NULL;
 	if (IS_ERR(rxcall)) {
 		ret = PTR_ERR(rxcall);
@@ -386,7 +370,10 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
 
 	/* at this point, an async call may no longer exist as it may have
 	 * already completed */
-	return wait_mode->wait(call);
+	if (call->async)
+		return -EINPROGRESS;
+
+	return afs_wait_for_call_to_complete(call);
 
 error_do_abort:
 	rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT, -ret, "KSD");
@@ -549,17 +536,6 @@ static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 }
 
 /*
- * put a call into asynchronous mode
- * - mustn't touch the call descriptor as the call my have completed by the
- *   time we get here
- */
-static int afs_dont_wait_for_call_to_complete(struct afs_call *call)
-{
-	_enter("");
-	return -EINPROGRESS;
-}
-
-/*
  * delete an asynchronous call
  */
 static void afs_delete_async_call(struct work_struct *work)
@@ -587,10 +563,7 @@ static void afs_process_async_call(struct work_struct *work)
 		afs_deliver_to_call(call);
 	}
 
-	if (call->state == AFS_CALL_COMPLETE && call->wait_mode) {
-		if (call->wait_mode->async_complete)
-			call->wait_mode->async_complete(call->reply,
-							call->error);
+	if (call->state == AFS_CALL_COMPLETE) {
 		call->reply = NULL;
 
 		/* kill the call */
@@ -626,10 +599,10 @@ static void afs_charge_preallocation(struct work_struct *work)
 				break;
 
 			INIT_WORK(&call->async_work, afs_process_async_call);
-			call->wait_mode = &afs_async_incoming_call;
 			call->type = &afs_RXCMxxxx;
-			init_waitqueue_head(&call->waitq);
+			call->async = true;
 			call->state = AFS_CALL_AWAIT_OP_ID;
+			init_waitqueue_head(&call->waitq);
 		}
 
 		if (rxrpc_kernel_charge_accept(afs_socket,
diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c
index 94bcd97d22b8..a5e4cc561b6c 100644
--- a/fs/afs/vlclient.c
+++ b/fs/afs/vlclient.c
@@ -147,7 +147,7 @@ int afs_vl_get_entry_by_name(struct in_addr *addr,
 			     struct key *key,
 			     const char *volname,
 			     struct afs_cache_vlocation *entry,
-			     const struct afs_wait_mode *wait_mode)
+			     bool async)
 {
 	struct afs_call *call;
 	size_t volnamesz, reqsz, padsz;
@@ -177,7 +177,7 @@ int afs_vl_get_entry_by_name(struct in_addr *addr,
 		memset((void *) bp + volnamesz, 0, padsz);
 
 	/* initiate the call */
-	return afs_make_call(addr, call, GFP_KERNEL, wait_mode);
+	return afs_make_call(addr, call, GFP_KERNEL, async);
 }
 
 /*
@@ -188,7 +188,7 @@ int afs_vl_get_entry_by_id(struct in_addr *addr,
 			   afs_volid_t volid,
 			   afs_voltype_t voltype,
 			   struct afs_cache_vlocation *entry,
-			   const struct afs_wait_mode *wait_mode)
+			   bool async)
 {
 	struct afs_call *call;
 	__be32 *bp;
@@ -211,5 +211,5 @@ int afs_vl_get_entry_by_id(struct in_addr *addr,
 	*bp   = htonl(voltype);
 
 	/* initiate the call */
-	return afs_make_call(addr, call, GFP_KERNEL, wait_mode);
+	return afs_make_call(addr, call, GFP_KERNEL, async);
 }
diff --git a/fs/afs/vlocation.c b/fs/afs/vlocation.c
index 45a86396fd2d..d7d8dd8c0b31 100644
--- a/fs/afs/vlocation.c
+++ b/fs/afs/vlocation.c
@@ -53,7 +53,7 @@ static int afs_vlocation_access_vl_by_name(struct afs_vlocation *vl,
 
 		/* attempt to access the VL server */
 		ret = afs_vl_get_entry_by_name(&addr, key, vl->vldb.name, vldb,
-					       &afs_sync_call);
+					       false);
 		switch (ret) {
 		case 0:
 			goto out;
@@ -111,7 +111,7 @@ static int afs_vlocation_access_vl_by_id(struct afs_vlocation *vl,
 
 		/* attempt to access the VL server */
 		ret = afs_vl_get_entry_by_id(&addr, key, volid, voltype, vldb,
-					     &afs_sync_call);
+					     false);
 		switch (ret) {
 		case 0:
 			goto out;
diff --git a/fs/afs/vnode.c b/fs/afs/vnode.c
index 45aa874f5d32..dcb956143c86 100644
--- a/fs/afs/vnode.c
+++ b/fs/afs/vnode.c
@@ -358,7 +358,7 @@ int afs_vnode_fetch_status(struct afs_vnode *vnode,
 		       server, ntohl(server->addr.s_addr));
 
 		ret = afs_fs_fetch_file_status(server, key, vnode, NULL,
-					       &afs_sync_call);
+					       false);
 
 	} while (!afs_volume_release_fileserver(vnode, server, ret));
 
@@ -421,7 +421,7 @@ int afs_vnode_fetch_data(struct afs_vnode *vnode, struct key *key,
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
 		ret = afs_fs_fetch_data(server, key, vnode, desc,
-					&afs_sync_call);
+					false);
 
 	} while (!afs_volume_release_fileserver(vnode, server, ret));
 
@@ -477,7 +477,7 @@ int afs_vnode_create(struct afs_vnode *vnode, struct key *key,
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
 		ret = afs_fs_create(server, key, vnode, name, mode, newfid,
-				    newstatus, newcb, &afs_sync_call);
+				    newstatus, newcb, false);
 
 	} while (!afs_volume_release_fileserver(vnode, server, ret));
 
@@ -533,7 +533,7 @@ int afs_vnode_remove(struct afs_vnode *vnode, struct key *key, const char *name,
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
 		ret = afs_fs_remove(server, key, vnode, name, isdir,
-				    &afs_sync_call);
+				    false);
 
 	} while (!afs_volume_release_fileserver(vnode, server, ret));
 
@@ -595,7 +595,7 @@ int afs_vnode_link(struct afs_vnode *dvnode, struct afs_vnode *vnode,
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
 		ret = afs_fs_link(server, key, dvnode, vnode, name,
-				  &afs_sync_call);
+				  false);
 
 	} while (!afs_volume_release_fileserver(dvnode, server, ret));
 
@@ -659,7 +659,7 @@ int afs_vnode_symlink(struct afs_vnode *vnode, struct key *key,
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
 		ret = afs_fs_symlink(server, key, vnode, name, content,
-				     newfid, newstatus, &afs_sync_call);
+				     newfid, newstatus, false);
 
 	} while (!afs_volume_release_fileserver(vnode, server, ret));
 
@@ -729,7 +729,7 @@ int afs_vnode_rename(struct afs_vnode *orig_dvnode,
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
 		ret = afs_fs_rename(server, key, orig_dvnode, orig_name,
-				    new_dvnode, new_name, &afs_sync_call);
+				    new_dvnode, new_name, false);
 
 	} while (!afs_volume_release_fileserver(orig_dvnode, server, ret));
 
@@ -795,7 +795,7 @@ int afs_vnode_store_data(struct afs_writeback *wb, pgoff_t first, pgoff_t last,
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
 		ret = afs_fs_store_data(server, wb, first, last, offset, to,
-					&afs_sync_call);
+					false);
 
 	} while (!afs_volume_release_fileserver(vnode, server, ret));
 
@@ -847,7 +847,7 @@ int afs_vnode_setattr(struct afs_vnode *vnode, struct key *key,
 
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
-		ret = afs_fs_setattr(server, key, vnode, attr, &afs_sync_call);
+		ret = afs_fs_setattr(server, key, vnode, attr, false);
 
 	} while (!afs_volume_release_fileserver(vnode, server, ret));
 
@@ -894,7 +894,7 @@ int afs_vnode_get_volume_status(struct afs_vnode *vnode, struct key *key,
 
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
-		ret = afs_fs_get_volume_status(server, key, vnode, vs, &afs_sync_call);
+		ret = afs_fs_get_volume_status(server, key, vnode, vs, false);
 
 	} while (!afs_volume_release_fileserver(vnode, server, ret));
 
@@ -933,7 +933,7 @@ int afs_vnode_set_lock(struct afs_vnode *vnode, struct key *key,
 
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
-		ret = afs_fs_set_lock(server, key, vnode, type, &afs_sync_call);
+		ret = afs_fs_set_lock(server, key, vnode, type, false);
 
 	} while (!afs_volume_release_fileserver(vnode, server, ret));
 
@@ -971,7 +971,7 @@ int afs_vnode_extend_lock(struct afs_vnode *vnode, struct key *key)
 
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
-		ret = afs_fs_extend_lock(server, key, vnode, &afs_sync_call);
+		ret = afs_fs_extend_lock(server, key, vnode, false);
 
 	} while (!afs_volume_release_fileserver(vnode, server, ret));
 
@@ -1009,7 +1009,7 @@ int afs_vnode_release_lock(struct afs_vnode *vnode, struct key *key)
 
 		_debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr));
 
-		ret = afs_fs_release_lock(server, key, vnode, &afs_sync_call);
+		ret = afs_fs_release_lock(server, key, vnode, false);
 
 	} while (!afs_volume_release_fileserver(vnode, server, ret));
 

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH net-next 3/4] rxrpc: Allow listen(sock, 0) to be used to disable listening
  2017-01-09 14:52 [PATCH net-next 0/4] afs: Refcount afs_call struct David Howells
  2017-01-09 14:52 ` [PATCH net-next 1/4] afs: Add some tracepoints David Howells
  2017-01-09 14:53 ` [PATCH net-next 2/4] afs: Kill afs_wait_mode David Howells
@ 2017-01-09 14:53 ` David Howells
  2017-01-09 14:53 ` [PATCH net-next 4/4] afs: Refcount the afs_call struct David Howells
  2017-01-09 20:48 ` [PATCH net-next 0/4] afs: Refcount " David Miller
  4 siblings, 0 replies; 6+ messages in thread
From: David Howells @ 2017-01-09 14:53 UTC (permalink / raw)
  To: netdev; +Cc: dhowells, linux-afs, linux-kernel

Allow listen() with a backlog of 0 to be used to disable listening on an
AF_RXRPC socket.  This also releases any preallocation, thereby making it
easier for a kernel service to account for all allocated call structures
when shutting down the service.

The socket cannot thereafter have listening reenabled, but must rather be
closed and reopened.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 net/rxrpc/af_rxrpc.c    |    8 ++++++++
 net/rxrpc/ar-internal.h |    1 +
 net/rxrpc/call_accept.c |    3 ++-
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 5f63f6dcaabb..199b46e93e64 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -224,6 +224,14 @@ static int rxrpc_listen(struct socket *sock, int backlog)
 		else
 			sk->sk_max_ack_backlog = old;
 		break;
+	case RXRPC_SERVER_LISTENING:
+		if (backlog == 0) {
+			rx->sk.sk_state = RXRPC_SERVER_LISTEN_DISABLED;
+			sk->sk_max_ack_backlog = 0;
+			rxrpc_discard_prealloc(rx);
+			ret = 0;
+			break;
+		}
 	default:
 		ret = -EBUSY;
 		break;
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 84927c7b5fdf..12be432be9b2 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -60,6 +60,7 @@ enum {
 	RXRPC_CLIENT_BOUND,		/* client local address bound */
 	RXRPC_SERVER_BOUND,		/* server local address bound */
 	RXRPC_SERVER_LISTENING,		/* server listening for connections */
+	RXRPC_SERVER_LISTEN_DISABLED,	/* server listening disabled */
 	RXRPC_CLOSE,			/* socket is being closed */
 };
 
diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
index 832d854c2d5c..7c4c64ab8da2 100644
--- a/net/rxrpc/call_accept.c
+++ b/net/rxrpc/call_accept.c
@@ -349,7 +349,8 @@ struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
 
 found_service:
 	spin_lock(&rx->incoming_lock);
-	if (rx->sk.sk_state == RXRPC_CLOSE) {
+	if (rx->sk.sk_state == RXRPC_SERVER_LISTEN_DISABLED ||
+	    rx->sk.sk_state == RXRPC_CLOSE) {
 		trace_rxrpc_abort("CLS", sp->hdr.cid, sp->hdr.callNumber,
 				  sp->hdr.seq, RX_INVALID_OPERATION, ESHUTDOWN);
 		skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT;

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH net-next 4/4] afs: Refcount the afs_call struct
  2017-01-09 14:52 [PATCH net-next 0/4] afs: Refcount afs_call struct David Howells
                   ` (2 preceding siblings ...)
  2017-01-09 14:53 ` [PATCH net-next 3/4] rxrpc: Allow listen(sock, 0) to be used to disable listening David Howells
@ 2017-01-09 14:53 ` David Howells
  2017-01-09 20:48 ` [PATCH net-next 0/4] afs: Refcount " David Miller
  4 siblings, 0 replies; 6+ messages in thread
From: David Howells @ 2017-01-09 14:53 UTC (permalink / raw)
  To: netdev; +Cc: dhowells, linux-afs, linux-kernel

A static checker warning occurs in the AFS filesystem:

	fs/afs/cmservice.c:155 SRXAFSCB_CallBack()
	error: dereferencing freed memory 'call'

due to the reply being sent before we access the server it points to.  The
act of sending the reply causes the call to be freed if an error occurs
(but not if it doesn't).

On top of this, the lifetime handling of afs_call structs is fragile
because they get passed around through workqueues without any sort of
refcounting.

Deal with the issues by:

 (1) Fix the maybe/maybe not nature of the reply sending functions with
     regards to whether they release the call struct.

 (2) Refcount the afs_call struct and sort out places that need to get/put
     references.

 (3) Pass a ref through the work queue and release (or pass on) that ref in
     the work function.  Care has to be taken because a work queue may
     already own a ref to the call.

 (4) Do the cleaning up in the put function only.

 (5) Simplify module cleanup by always incrementing afs_outstanding_calls
     whenever a call is allocated.

 (6) Set the backlog to 0 with kernel_listen() at the beginning of the
     process of closing the socket to prevent new incoming calls from
     occurring and to remove the contribution of preallocated calls from
     afs_outstanding_calls before we wait on it.

A tracepoint is also added to monitor the afs_call refcount and lifetime.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Fixes: 08e0e7c82eea: "[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC."
---

 fs/afs/cmservice.c         |   41 ++++++------
 fs/afs/internal.h          |    9 ++-
 fs/afs/rxrpc.c             |  153 +++++++++++++++++++++++++++-----------------
 include/trace/events/afs.h |   75 ++++++++++++++++++++++
 4 files changed, 199 insertions(+), 79 deletions(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index a2e1e02005f6..e349a3316303 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -24,6 +24,11 @@ static int afs_deliver_cb_callback(struct afs_call *);
 static int afs_deliver_cb_probe_uuid(struct afs_call *);
 static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *);
 static void afs_cm_destructor(struct afs_call *);
+static void SRXAFSCB_CallBack(struct work_struct *);
+static void SRXAFSCB_InitCallBackState(struct work_struct *);
+static void SRXAFSCB_Probe(struct work_struct *);
+static void SRXAFSCB_ProbeUuid(struct work_struct *);
+static void SRXAFSCB_TellMeAboutYourself(struct work_struct *);
 
 #define CM_NAME(name) \
 	const char afs_SRXCB##name##_name[] __tracepoint_string =	\
@@ -38,6 +43,7 @@ static const struct afs_call_type afs_SRXCBCallBack = {
 	.deliver	= afs_deliver_cb_callback,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
+	.work		= SRXAFSCB_CallBack,
 };
 
 /*
@@ -49,6 +55,7 @@ static const struct afs_call_type afs_SRXCBInitCallBackState = {
 	.deliver	= afs_deliver_cb_init_call_back_state,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
+	.work		= SRXAFSCB_InitCallBackState,
 };
 
 /*
@@ -60,6 +67,7 @@ static const struct afs_call_type afs_SRXCBInitCallBackState3 = {
 	.deliver	= afs_deliver_cb_init_call_back_state3,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
+	.work		= SRXAFSCB_InitCallBackState,
 };
 
 /*
@@ -71,6 +79,7 @@ static const struct afs_call_type afs_SRXCBProbe = {
 	.deliver	= afs_deliver_cb_probe,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
+	.work		= SRXAFSCB_Probe,
 };
 
 /*
@@ -82,6 +91,7 @@ static const struct afs_call_type afs_SRXCBProbeUuid = {
 	.deliver	= afs_deliver_cb_probe_uuid,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
+	.work		= SRXAFSCB_ProbeUuid,
 };
 
 /*
@@ -93,6 +103,7 @@ static const struct afs_call_type afs_SRXCBTellMeAboutYourself = {
 	.deliver	= afs_deliver_cb_tell_me_about_yourself,
 	.abort_to_error	= afs_abort_to_error,
 	.destructor	= afs_cm_destructor,
+	.work		= SRXAFSCB_TellMeAboutYourself,
 };
 
 /*
@@ -163,6 +174,7 @@ static void SRXAFSCB_CallBack(struct work_struct *work)
 	afs_send_empty_reply(call);
 
 	afs_break_callbacks(call->server, call->count, call->request);
+	afs_put_call(call);
 	_leave("");
 }
 
@@ -284,9 +296,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		return -ENOTCONN;
 	call->server = server;
 
-	INIT_WORK(&call->work, SRXAFSCB_CallBack);
-	queue_work(afs_wq, &call->work);
-	return 0;
+	return afs_queue_call_work(call);
 }
 
 /*
@@ -300,6 +310,7 @@ static void SRXAFSCB_InitCallBackState(struct work_struct *work)
 
 	afs_init_callback_state(call->server);
 	afs_send_empty_reply(call);
+	afs_put_call(call);
 	_leave("");
 }
 
@@ -330,9 +341,7 @@ static int afs_deliver_cb_init_call_back_state(struct afs_call *call)
 		return -ENOTCONN;
 	call->server = server;
 
-	INIT_WORK(&call->work, SRXAFSCB_InitCallBackState);
-	queue_work(afs_wq, &call->work);
-	return 0;
+	return afs_queue_call_work(call);
 }
 
 /*
@@ -404,9 +413,7 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
 		return -ENOTCONN;
 	call->server = server;
 
-	INIT_WORK(&call->work, SRXAFSCB_InitCallBackState);
-	queue_work(afs_wq, &call->work);
-	return 0;
+	return afs_queue_call_work(call);
 }
 
 /*
@@ -418,6 +425,7 @@ static void SRXAFSCB_Probe(struct work_struct *work)
 
 	_enter("");
 	afs_send_empty_reply(call);
+	afs_put_call(call);
 	_leave("");
 }
 
@@ -437,9 +445,7 @@ static int afs_deliver_cb_probe(struct afs_call *call)
 	/* no unmarshalling required */
 	call->state = AFS_CALL_REPLYING;
 
-	INIT_WORK(&call->work, SRXAFSCB_Probe);
-	queue_work(afs_wq, &call->work);
-	return 0;
+	return afs_queue_call_work(call);
 }
 
 /*
@@ -462,6 +468,7 @@ static void SRXAFSCB_ProbeUuid(struct work_struct *work)
 		reply.match = htonl(1);
 
 	afs_send_simple_reply(call, &reply, sizeof(reply));
+	afs_put_call(call);
 	_leave("");
 }
 
@@ -520,9 +527,7 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 
 	call->state = AFS_CALL_REPLYING;
 
-	INIT_WORK(&call->work, SRXAFSCB_ProbeUuid);
-	queue_work(afs_wq, &call->work);
-	return 0;
+	return afs_queue_call_work(call);
 }
 
 /*
@@ -584,7 +589,7 @@ static void SRXAFSCB_TellMeAboutYourself(struct work_struct *work)
 	reply.cap.capcount = htonl(1);
 	reply.cap.caps[0] = htonl(AFS_CAP_ERROR_TRANSLATION);
 	afs_send_simple_reply(call, &reply, sizeof(reply));
-
+	afs_put_call(call);
 	_leave("");
 }
 
@@ -604,7 +609,5 @@ static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *call)
 	/* no unmarshalling required */
 	call->state = AFS_CALL_REPLYING;
 
-	INIT_WORK(&call->work, SRXAFSCB_TellMeAboutYourself);
-	queue_work(afs_wq, &call->work);
-	return 0;
+	return afs_queue_call_work(call);
 }
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index b411670d5f67..65504e218d35 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -66,7 +66,7 @@ enum afs_call_state {
 struct afs_call {
 	const struct afs_call_type *type;	/* type of call */
 	wait_queue_head_t	waitq;		/* processes awaiting completion */
-	struct work_struct	async_work;	/* asynchronous work processor */
+	struct work_struct	async_work;	/* async I/O processor */
 	struct work_struct	work;		/* actual work processor */
 	struct rxrpc_call	*rxcall;	/* RxRPC call handle */
 	struct key		*key;		/* security for this call */
@@ -82,6 +82,7 @@ struct afs_call {
 	pgoff_t			first;		/* first page in mapping to deal with */
 	pgoff_t			last;		/* last page in mapping to deal with */
 	size_t			offset;		/* offset into received data store */
+	atomic_t		usage;
 	enum afs_call_state	state;
 	int			error;		/* error code */
 	u32			abort_code;	/* Remote abort ID or 0 */
@@ -115,6 +116,9 @@ struct afs_call_type {
 
 	/* clean up a call */
 	void (*destructor)(struct afs_call *call);
+
+	/* Work function */
+	void (*work)(struct work_struct *work);
 };
 
 /*
@@ -591,9 +595,12 @@ extern void afs_proc_cell_remove(struct afs_cell *);
  * rxrpc.c
  */
 extern struct socket *afs_socket;
+extern atomic_t afs_outstanding_calls;
 
 extern int afs_open_socket(void);
 extern void afs_close_socket(void);
+extern void afs_put_call(struct afs_call *);
+extern int afs_queue_call_work(struct afs_call *);
 extern int afs_make_call(struct in_addr *, struct afs_call *, gfp_t, bool);
 extern struct afs_call *afs_alloc_flat_call(const struct afs_call_type *,
 					    size_t, size_t);
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index ec1e41f929d1..95f42872b787 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -19,9 +19,8 @@
 struct socket *afs_socket; /* my RxRPC socket */
 static struct workqueue_struct *afs_async_calls;
 static struct afs_call *afs_spare_incoming_call;
-static atomic_t afs_outstanding_calls;
+atomic_t afs_outstanding_calls;
 
-static void afs_free_call(struct afs_call *);
 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
 static int afs_wait_for_call_to_complete(struct afs_call *);
 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
@@ -112,9 +111,11 @@ void afs_close_socket(void)
 {
 	_enter("");
 
+	kernel_listen(afs_socket, 0);
+	flush_workqueue(afs_async_calls);
+
 	if (afs_spare_incoming_call) {
-		atomic_inc(&afs_outstanding_calls);
-		afs_free_call(afs_spare_incoming_call);
+		afs_put_call(afs_spare_incoming_call);
 		afs_spare_incoming_call = NULL;
 	}
 
@@ -123,7 +124,6 @@ void afs_close_socket(void)
 			 TASK_UNINTERRUPTIBLE);
 	_debug("no outstanding calls");
 
-	flush_workqueue(afs_async_calls);
 	kernel_sock_shutdown(afs_socket, SHUT_RDWR);
 	flush_workqueue(afs_async_calls);
 	sock_release(afs_socket);
@@ -134,44 +134,79 @@ void afs_close_socket(void)
 }
 
 /*
- * free a call
+ * Allocate a call.
  */
-static void afs_free_call(struct afs_call *call)
+static struct afs_call *afs_alloc_call(const struct afs_call_type *type,
+				       gfp_t gfp)
 {
-	_debug("DONE %p{%s} [%d]",
-	       call, call->type->name, atomic_read(&afs_outstanding_calls));
+	struct afs_call *call;
+	int o;
 
-	ASSERTCMP(call->rxcall, ==, NULL);
-	ASSERT(!work_pending(&call->async_work));
-	ASSERT(call->type->name != NULL);
+	call = kzalloc(sizeof(*call), gfp);
+	if (!call)
+		return NULL;
 
-	kfree(call->request);
-	kfree(call);
+	call->type = type;
+	atomic_set(&call->usage, 1);
+	INIT_WORK(&call->async_work, afs_process_async_call);
+	init_waitqueue_head(&call->waitq);
 
-	if (atomic_dec_and_test(&afs_outstanding_calls))
-		wake_up_atomic_t(&afs_outstanding_calls);
+	o = atomic_inc_return(&afs_outstanding_calls);
+	trace_afs_call(call, afs_call_trace_alloc, 1, o,
+		       __builtin_return_address(0));
+	return call;
 }
 
 /*
- * End a call but do not free it
+ * Dispose of a reference on a call.
  */
-static void afs_end_call_nofree(struct afs_call *call)
+void afs_put_call(struct afs_call *call)
 {
-	if (call->rxcall) {
-		rxrpc_kernel_end_call(afs_socket, call->rxcall);
-		call->rxcall = NULL;
+	int n = atomic_dec_return(&call->usage);
+	int o = atomic_read(&afs_outstanding_calls);
+
+	trace_afs_call(call, afs_call_trace_put, n + 1, o,
+		       __builtin_return_address(0));
+
+	ASSERTCMP(n, >=, 0);
+	if (n == 0) {
+		ASSERT(!work_pending(&call->async_work));
+		ASSERT(call->type->name != NULL);
+
+		if (call->rxcall) {
+			rxrpc_kernel_end_call(afs_socket, call->rxcall);
+			call->rxcall = NULL;
+		}
+		if (call->type->destructor)
+			call->type->destructor(call);
+
+		kfree(call->request);
+		kfree(call);
+
+		o = atomic_dec_return(&afs_outstanding_calls);
+		trace_afs_call(call, afs_call_trace_free, 0, o,
+			       __builtin_return_address(0));
+		if (o == 0)
+			wake_up_atomic_t(&afs_outstanding_calls);
 	}
-	if (call->type->destructor)
-		call->type->destructor(call);
 }
 
 /*
- * End a call and free it
+ * Queue the call for actual work.  Returns 0 unconditionally for convenience.
  */
-static void afs_end_call(struct afs_call *call)
+int afs_queue_call_work(struct afs_call *call)
 {
-	afs_end_call_nofree(call);
-	afs_free_call(call);
+	int u = atomic_inc_return(&call->usage);
+
+	trace_afs_call(call, afs_call_trace_work, u,
+		       atomic_read(&afs_outstanding_calls),
+		       __builtin_return_address(0));
+
+	INIT_WORK(&call->work, call->type->work);
+
+	if (!queue_work(afs_wq, &call->work))
+		afs_put_call(call);
+	return 0;
 }
 
 /*
@@ -182,25 +217,19 @@ struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
 {
 	struct afs_call *call;
 
-	call = kzalloc(sizeof(*call), GFP_NOFS);
+	call = afs_alloc_call(type, GFP_NOFS);
 	if (!call)
 		goto nomem_call;
 
-	_debug("CALL %p{%s} [%d]",
-	       call, type->name, atomic_read(&afs_outstanding_calls));
-	atomic_inc(&afs_outstanding_calls);
-
-	call->type = type;
-	call->request_size = request_size;
-	call->reply_max = reply_max;
-
 	if (request_size) {
+		call->request_size = request_size;
 		call->request = kmalloc(request_size, GFP_NOFS);
 		if (!call->request)
 			goto nomem_free;
 	}
 
 	if (reply_max) {
+		call->reply_max = reply_max;
 		call->buffer = kmalloc(reply_max, GFP_NOFS);
 		if (!call->buffer)
 			goto nomem_free;
@@ -210,7 +239,7 @@ struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
 	return call;
 
 nomem_free:
-	afs_free_call(call);
+	afs_put_call(call);
 nomem_call:
 	return NULL;
 }
@@ -315,7 +344,6 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
 	       atomic_read(&afs_outstanding_calls));
 
 	call->async = async;
-	INIT_WORK(&call->async_work, afs_process_async_call);
 
 	memset(&srx, 0, sizeof(srx));
 	srx.srx_family = AF_RXRPC;
@@ -378,7 +406,7 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
 error_do_abort:
 	rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT, -ret, "KSD");
 error_kill_call:
-	afs_end_call(call);
+	afs_put_call(call);
 	_leave(" = %d", ret);
 	return ret;
 }
@@ -448,7 +476,7 @@ static void afs_deliver_to_call(struct afs_call *call)
 
 done:
 	if (call->state == AFS_CALL_COMPLETE && call->incoming)
-		afs_end_call(call);
+		afs_put_call(call);
 out:
 	_leave("");
 	return;
@@ -505,7 +533,7 @@ static int afs_wait_for_call_to_complete(struct afs_call *call)
 	}
 
 	_debug("call complete");
-	afs_end_call(call);
+	afs_put_call(call);
 	_leave(" = %d", ret);
 	return ret;
 }
@@ -529,14 +557,25 @@ static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 				   unsigned long call_user_ID)
 {
 	struct afs_call *call = (struct afs_call *)call_user_ID;
+	int u;
 
 	trace_afs_notify_call(rxcall, call);
 	call->need_attention = true;
-	queue_work(afs_async_calls, &call->async_work);
+
+	u = __atomic_add_unless(&call->usage, 1, 0);
+	if (u != 0) {
+		trace_afs_call(call, afs_call_trace_wake, u,
+			       atomic_read(&afs_outstanding_calls),
+			       __builtin_return_address(0));
+
+		if (!queue_work(afs_async_calls, &call->async_work))
+			afs_put_call(call);
+	}
 }
 
 /*
- * delete an asynchronous call
+ * Delete an asynchronous call.  The work item carries a ref to the call struct
+ * that we need to release.
  */
 static void afs_delete_async_call(struct work_struct *work)
 {
@@ -544,13 +583,14 @@ static void afs_delete_async_call(struct work_struct *work)
 
 	_enter("");
 
-	afs_free_call(call);
+	afs_put_call(call);
 
 	_leave("");
 }
 
 /*
- * perform processing on an asynchronous call
+ * Perform I/O processing on an asynchronous call.  The work item carries a ref
+ * to the call struct that we either need to release or to pass on.
  */
 static void afs_process_async_call(struct work_struct *work)
 {
@@ -566,15 +606,16 @@ static void afs_process_async_call(struct work_struct *work)
 	if (call->state == AFS_CALL_COMPLETE) {
 		call->reply = NULL;
 
-		/* kill the call */
-		afs_end_call_nofree(call);
-
-		/* we can't just delete the call because the work item may be
-		 * queued */
+		/* We have two refs to release - one from the alloc and one
+		 * queued with the work item - and we can't just deallocate the
+		 * call because the work item may be queued again.
+		 */
 		call->async_work.func = afs_delete_async_call;
-		queue_work(afs_async_calls, &call->async_work);
+		if (!queue_work(afs_async_calls, &call->async_work))
+			afs_put_call(call);
 	}
 
+	afs_put_call(call);
 	_leave("");
 }
 
@@ -594,12 +635,10 @@ static void afs_charge_preallocation(struct work_struct *work)
 
 	for (;;) {
 		if (!call) {
-			call = kzalloc(sizeof(struct afs_call), GFP_KERNEL);
+			call = afs_alloc_call(&afs_RXCMxxxx, GFP_KERNEL);
 			if (!call)
 				break;
 
-			INIT_WORK(&call->async_work, afs_process_async_call);
-			call->type = &afs_RXCMxxxx;
 			call->async = true;
 			call->state = AFS_CALL_AWAIT_OP_ID;
 			init_waitqueue_head(&call->waitq);
@@ -624,9 +663,8 @@ static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 {
 	struct afs_call *call = (struct afs_call *)user_call_ID;
 
-	atomic_inc(&afs_outstanding_calls);
 	call->rxcall = NULL;
-	afs_free_call(call);
+	afs_put_call(call);
 }
 
 /*
@@ -635,7 +673,6 @@ static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 			    unsigned long user_call_ID)
 {
-	atomic_inc(&afs_outstanding_calls);
 	queue_work(afs_wq, &afs_charge_preallocation_work);
 }
 
@@ -699,7 +736,6 @@ void afs_send_empty_reply(struct afs_call *call)
 		rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 					RX_USER_ABORT, ENOMEM, "KOO");
 	default:
-		afs_end_call(call);
 		_leave(" [error]");
 		return;
 	}
@@ -738,7 +774,6 @@ void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 		rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 					RX_USER_ABORT, ENOMEM, "KOO");
 	}
-	afs_end_call(call);
 	_leave(" [error]");
 }
 
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 845907b04ff4..8b95c16b7045 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -16,6 +16,51 @@
 
 #include <linux/tracepoint.h>
 
+/*
+ * Define enums for tracing information.
+ */
+#ifndef __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
+#define __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
+
+enum afs_call_trace {
+	afs_call_trace_alloc,
+	afs_call_trace_free,
+	afs_call_trace_put,
+	afs_call_trace_wake,
+	afs_call_trace_work,
+};
+
+#endif /* end __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY */
+
+/*
+ * Declare tracing information enums and their string mappings for display.
+ */
+#define afs_call_traces \
+	EM(afs_call_trace_alloc,		"ALLOC") \
+	EM(afs_call_trace_free,			"FREE ") \
+	EM(afs_call_trace_put,			"PUT  ") \
+	EM(afs_call_trace_wake,			"WAKE ") \
+	E_(afs_call_trace_work,			"WORK ")
+
+/*
+ * Export enum symbols via userspace.
+ */
+#undef EM
+#undef E_
+#define EM(a, b) TRACE_DEFINE_ENUM(a);
+#define E_(a, b) TRACE_DEFINE_ENUM(a);
+
+afs_call_traces;
+
+/*
+ * Now redefine the EM() and E_() macros to map the enums to the strings that
+ * will be printed in the output.
+ */
+#undef EM
+#undef E_
+#define EM(a, b)	{ a, b },
+#define E_(a, b)	{ a, b }
+
 TRACE_EVENT(afs_recv_data,
 	    TP_PROTO(struct afs_call *call, unsigned count, unsigned offset,
 		     bool want_more, int ret),
@@ -103,6 +148,36 @@ TRACE_EVENT(afs_cb_call,
 		      __entry->op)
 	    );
 
+TRACE_EVENT(afs_call,
+	    TP_PROTO(struct afs_call *call, enum afs_call_trace op,
+		     int usage, int outstanding, const void *where),
+
+	    TP_ARGS(call, op, usage, outstanding, where),
+
+	    TP_STRUCT__entry(
+		    __field(struct afs_call *,		call		)
+		    __field(int,			op		)
+		    __field(int,			usage		)
+		    __field(int,			outstanding	)
+		    __field(const void *,		where		)
+			     ),
+
+	    TP_fast_assign(
+		    __entry->call = call;
+		    __entry->op = op;
+		    __entry->usage = usage;
+		    __entry->outstanding = outstanding;
+		    __entry->where = where;
+			   ),
+
+	    TP_printk("c=%p %s u=%d o=%d sp=%pSR",
+		      __entry->call,
+		      __print_symbolic(__entry->op, afs_call_traces),
+		      __entry->usage,
+		      __entry->outstanding,
+		      __entry->where)
+	    );
+
 #endif /* _TRACE_AFS_H */
 
 /* This part must be outside protection */

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH net-next 0/4] afs: Refcount afs_call struct
  2017-01-09 14:52 [PATCH net-next 0/4] afs: Refcount afs_call struct David Howells
                   ` (3 preceding siblings ...)
  2017-01-09 14:53 ` [PATCH net-next 4/4] afs: Refcount the afs_call struct David Howells
@ 2017-01-09 20:48 ` David Miller
  4 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2017-01-09 20:48 UTC (permalink / raw)
  To: dhowells; +Cc: netdev, linux-afs, linux-kernel

From: David Howells <dhowells@redhat.com>
Date: Mon, 09 Jan 2017 14:52:49 +0000

> 
> These patches provide some tracepoints for AFS and fix a potential leak by
> adding refcounting to the afs_call struct.
> 
> The patches are:
> 
>  (1) Add some tracepoints for logging incoming calls and monitoring
>      notifications from AF_RXRPC and data reception.
> 
>  (2) Get rid of afs_wait_mode as it didn't turn out to be as useful as
>      initially expected.  It can be brought back later if needed.  This
>      clears some stuff out that I don't then need to fix up in (4).
> 
>  (3) Allow listen(..., 0) to be used to disable listening.  This makes
>      shutting down the AFS cache manager server in the kernel much easier
>      and the accounting simpler as we can then be sure that (a) all
>      preallocated afs_call structs are relesed and (b) no new incoming
>      calls are going to be started.
> 
>      For the moment, listening cannot be reenabled.
> 
>  (4) Add refcounting to the afs_call struct to fix a potential multiple
>      release detected by static checking and add a tracepoint to follow the
>      lifecycle of afs_call objects.
> 
> The patches can be found here also:
> 
> 	http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-rewrite
> 
> Tagged thusly:
> 
> 	git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git
> 	rxrpc-rewrite-20170109

Pulled, thanks David.

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2017-01-09 20:48 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-01-09 14:52 [PATCH net-next 0/4] afs: Refcount afs_call struct David Howells
2017-01-09 14:52 ` [PATCH net-next 1/4] afs: Add some tracepoints David Howells
2017-01-09 14:53 ` [PATCH net-next 2/4] afs: Kill afs_wait_mode David Howells
2017-01-09 14:53 ` [PATCH net-next 3/4] rxrpc: Allow listen(sock, 0) to be used to disable listening David Howells
2017-01-09 14:53 ` [PATCH net-next 4/4] afs: Refcount the afs_call struct David Howells
2017-01-09 20:48 ` [PATCH net-next 0/4] afs: Refcount " David Miller

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