[PATCH net v10 01/14] rxrpc: Fix lack of short-send handling in rxrpc_kernel_send_data()
From: David Howells
Date: Mon Sep 14 2026 - 11:50:20 EST
Fix rxrpc_kernel_send_data() to loop around if it detects a short send.
David Laight suggested doing it here rather than wrapping all the calls in
loops. Further, remove the len argument and use the iterator count instead
and return 0 on success, not the amount copied.
Note this is also a prerequisite for changing the way rxrpc_send_data()
works to return a short send rather than an error if some data was
buffered.
Fixes: 651350d10f93 ("[AF_RXRPC]: Add an interface to the AF_RXRPC module for the AFS filesystem to use")
Link: https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260824091645.415423-1-dhowells%40redhat.com
Suggested-by: David Laight <david.laight.linux@xxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
cc: Eric Dumazet <edumazet@xxxxxxxxxx>
cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
cc: Jakub Kicinski <kuba@xxxxxxxxxx>
cc: Paolo Abeni <pabeni@xxxxxxxxxx>
cc: Simon Horman <horms@xxxxxxxxxx>
cc: linux-afs@xxxxxxxxxxxxxxxxxxx
cc: stable@xxxxxxxxxxxxxxx
---
Documentation/networking/rxrpc.rst | 6 ++++--
fs/afs/rxrpc.c | 28 ++++++++++----------------
include/net/af_rxrpc.h | 5 ++---
net/rxrpc/rxperf.c | 11 +++-------
net/rxrpc/sendmsg.c | 32 ++++++++++++++++++++----------
5 files changed, 42 insertions(+), 40 deletions(-)
diff --git a/Documentation/networking/rxrpc.rst b/Documentation/networking/rxrpc.rst
index 8926dab8e2e6..01ad12fdf305 100644
--- a/Documentation/networking/rxrpc.rst
+++ b/Documentation/networking/rxrpc.rst
@@ -870,7 +870,6 @@ The kernel interface functions are as follows:
int rxrpc_kernel_send_data(struct socket *sock,
struct rxrpc_call *call,
struct msghdr *msg,
- size_t len,
rxrpc_notify_end_tx_t notify_end_rx);
This is used to supply either the request part of a client call or the
@@ -880,13 +879,16 @@ The kernel interface functions are as follows:
MSG_MORE if there will be subsequent data sends for this call.
The msg must not specify a destination address, control data or any flags
- other than MSG_MORE. len is the total amount of data to transmit.
+ other than MSG_MORE.
notify_end_rx can be NULL or it can be used to specify a function to be
called when the call changes state to end the Tx phase. This function is
called with a spinlock held to prevent the last DATA packet from being
transmitted until the function returns.
+ It returns 0 if all the data is queued and a negative error code on
+ failure.
+
(#) Receive data from a call::
int rxrpc_kernel_recv_data(struct socket *sock,
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index d82916657a3d..09d9da92a1be 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -412,8 +412,7 @@ void afs_make_call(struct afs_call *call, gfp_t gfp)
msg.msg_controllen = 0;
msg.msg_flags = MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);
- ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
- &msg, call->request_size,
+ ret = rxrpc_kernel_send_data(call->net->socket, rxcall, &msg,
afs_notify_end_request_tx);
if (ret < 0)
goto error_do_abort;
@@ -425,7 +424,6 @@ void afs_make_call(struct afs_call *call, gfp_t gfp)
ret = rxrpc_kernel_send_data(call->net->socket,
call->rxcall, &msg,
- iov_iter_count(&msg.msg_iter),
afs_notify_end_request_tx);
*call->write_iter = msg.msg_iter;
@@ -871,7 +869,7 @@ void afs_send_empty_reply(struct afs_call *call)
msg.msg_controllen = 0;
msg.msg_flags = 0;
- switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
+ switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg,
afs_notify_end_reply_tx)) {
case 0:
_leave(" [replied]");
@@ -912,21 +910,17 @@ void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
msg.msg_controllen = 0;
msg.msg_flags = 0;
- n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
+ n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg,
afs_notify_end_reply_tx);
- if (n >= 0) {
- /* Success */
- _leave(" [replied]");
- return;
- }
-
- if (n == -ENOMEM) {
- _debug("oom");
- rxrpc_kernel_abort_call(net->socket, call->rxcall,
- RXGEN_SS_MARSHAL, -ENOMEM,
- afs_abort_oom);
+ if (n < 0) {
+ if (n == -ENOMEM) {
+ _debug("oom");
+ rxrpc_kernel_abort_call(net->socket, call->rxcall,
+ RXGEN_SS_MARSHAL, -ENOMEM,
+ afs_abort_oom);
+ }
+ _leave(" [error]");
}
- _leave(" [error]");
}
/*
diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h
index 0fb4c41c9bbf..f3980348ed34 100644
--- a/include/net/af_rxrpc.h
+++ b/include/net/af_rxrpc.h
@@ -64,9 +64,8 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock,
bool upgrade,
enum rxrpc_interruptibility interruptibility,
unsigned int debug_id);
-int rxrpc_kernel_send_data(struct socket *, struct rxrpc_call *,
- struct msghdr *, size_t,
- rxrpc_notify_end_tx_t);
+int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
+ struct msghdr *msg, rxrpc_notify_end_tx_t notify_end_tx);
int rxrpc_kernel_recv_data(struct socket *, struct rxrpc_call *,
struct iov_iter *, size_t *, bool, u32 *, u16 *);
bool rxrpc_kernel_abort_call(struct socket *, struct rxrpc_call *,
diff --git a/net/rxrpc/rxperf.c b/net/rxrpc/rxperf.c
index b8df6d22314d..dad04062213f 100644
--- a/net/rxrpc/rxperf.c
+++ b/net/rxrpc/rxperf.c
@@ -525,12 +525,10 @@ static int rxperf_process_call(struct rxperf_call *call)
iov_iter_bvec(&msg.msg_iter, WRITE, &bv, 1, len);
msg.msg_flags = MSG_MORE;
n = rxrpc_kernel_send_data(rxperf_socket, call->rxcall, &msg,
- len, rxperf_notify_end_reply_tx);
+ rxperf_notify_end_reply_tx);
if (n < 0)
return n;
- if (n == 0)
- return -EIO;
- reply_len -= n;
+ reply_len -= len;
}
len = sizeof(rxperf_magic_cookie);
@@ -538,11 +536,8 @@ static int rxperf_process_call(struct rxperf_call *call)
iov[0].iov_len = len;
iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
msg.msg_flags = 0;
- n = rxrpc_kernel_send_data(rxperf_socket, call->rxcall, &msg, len,
+ n = rxrpc_kernel_send_data(rxperf_socket, call->rxcall, &msg,
rxperf_notify_end_reply_tx);
- if (n >= 0)
- return 0; /* Success */
-
if (n == -ENOMEM)
rxrpc_kernel_abort_call(rxperf_socket, call->rxcall,
RXGEN_SS_MARSHAL, -ENOMEM,
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index ed2c9a51005a..34aae8e789a4 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -794,7 +794,6 @@ int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
* @sock: The socket the call is on
* @call: The call to send data through
* @msg: The data to send
- * @len: The amount of data to send
* @notify_end_tx: Notification that the last packet is queued.
*
* Allow a kernel service to send data on a call. The call must be in an state
@@ -805,8 +804,7 @@ int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
* Return: %0 if successful and a negative error code otherwise.
*/
int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
- struct msghdr *msg, size_t len,
- rxrpc_notify_end_tx_t notify_end_tx)
+ struct msghdr *msg, rxrpc_notify_end_tx_t notify_end_tx)
{
bool dropped_lock = false;
int ret;
@@ -816,15 +814,29 @@ int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
ASSERTCMP(msg->msg_name, ==, NULL);
ASSERTCMP(msg->msg_control, ==, NULL);
- mutex_lock(&call->user_mutex);
+ for (;;) {
+ mutex_lock(&call->user_mutex);
- ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
- notify_end_tx, &dropped_lock);
- if (ret == -ESHUTDOWN)
- ret = call->error;
+ ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg,
+ msg_data_left(msg),
+ notify_end_tx, &dropped_lock);
+ if (ret == -ESHUTDOWN)
+ ret = call->error;
+
+ if (!dropped_lock)
+ mutex_unlock(&call->user_mutex);
+ if (ret < 0)
+ break;
+ if (msg_data_left(msg) == 0) {
+ ret = 0;
+ break;
+ }
+ if (ret == 0) {
+ ret = -EIO;
+ break;
+ }
+ }
- if (!dropped_lock)
- mutex_unlock(&call->user_mutex);
_leave(" = %d", ret);
return ret;
}