[RFC PATCH 49/61] afs: Don't truncate iter during data fetch
From: David Howells
Date: Mon May 04 2020 - 13:15:06 EST
Don't truncate the iterator to correspond to the actual data size when
fetching the data from the server - rather, pass the length we want to read
to rxrpc.
This will allow the clear-after-read code in future to simply clear the
remaining iterator capacity rather than having to reinitialise the
iterator.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
fs/afs/fsclient.c | 6 ++++--
fs/afs/internal.h | 6 ++++++
fs/afs/rxrpc.c | 13 +++++++++----
fs/afs/yfsclient.c | 6 ++++--
include/net/af_rxrpc.h | 2 +-
net/rxrpc/recvmsg.c | 9 +++++----
6 files changed, 29 insertions(+), 13 deletions(-)
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 68fc46634346..492fbd964576 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -327,8 +327,9 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
unsigned int size;
int ret;
- _enter("{%u,%zu/%llu}",
- call->unmarshall, iov_iter_count(call->iter), req->actual_len);
+ _enter("{%u,%zu,%zu/%llu}",
+ call->unmarshall, call->iov_len, iov_iter_count(call->iter),
+ req->actual_len);
switch (call->unmarshall) {
case 0:
@@ -365,6 +366,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
size = PAGE_SIZE - req->offset;
else
size = req->remain;
+ call->iov_len = size;
call->bvec[0].bv_len = size;
call->bvec[0].bv_offset = req->offset;
call->bvec[0].bv_page = req->pages[req->index];
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 68d3eb0dc367..521a03023112 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -115,6 +115,7 @@ struct afs_call {
struct afs_vnode *lvnode; /* vnode being locked */
void *request; /* request data (first part) */
struct address_space *mapping; /* Pages being written from */
+ size_t iov_len; /* Size of *iter to be used */
struct iov_iter def_iter; /* Default buffer/data iterator */
struct iov_iter *iter; /* Iterator currently in use */
union { /* Convenience for ->def_iter */
@@ -1131,6 +1132,7 @@ static inline void afs_set_fc_call(struct afs_call *call, struct afs_fs_cursor *
static inline void afs_extract_begin(struct afs_call *call, void *buf, size_t size)
{
+ call->iov_len = size;
call->kvec[0].iov_base = buf;
call->kvec[0].iov_len = size;
iov_iter_kvec(&call->def_iter, READ, call->kvec, 1, size);
@@ -1138,21 +1140,25 @@ static inline void afs_extract_begin(struct afs_call *call, void *buf, size_t si
static inline void afs_extract_to_tmp(struct afs_call *call)
{
+ call->iov_len = sizeof(call->tmp);
afs_extract_begin(call, &call->tmp, sizeof(call->tmp));
}
static inline void afs_extract_to_tmp64(struct afs_call *call)
{
+ call->iov_len = sizeof(call->tmp64);
afs_extract_begin(call, &call->tmp64, sizeof(call->tmp64));
}
static inline void afs_extract_discard(struct afs_call *call, size_t size)
{
+ call->iov_len = size;
iov_iter_discard(&call->def_iter, READ, size);
}
static inline void afs_extract_to_buf(struct afs_call *call, size_t size)
{
+ call->iov_len = size;
afs_extract_begin(call, call->buffer, size);
}
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 1ecc67da6c1a..b2296feaaff3 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -364,6 +364,7 @@ void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
struct rxrpc_call *rxcall;
struct msghdr msg;
struct kvec iov[1];
+ size_t len;
s64 tx_total_len;
int ret;
@@ -465,9 +466,10 @@ void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
rxrpc_kernel_abort_call(call->net->socket, rxcall,
RX_USER_ABORT, ret, "KSD");
} else {
+ len = 0;
iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
rxrpc_kernel_recv_data(call->net->socket, rxcall,
- &msg.msg_iter, false,
+ &msg.msg_iter, &len, false,
&call->abort_code, &call->service_id);
ac->abort_code = call->abort_code;
ac->responded = true;
@@ -503,6 +505,7 @@ void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
static void afs_deliver_to_call(struct afs_call *call)
{
enum afs_call_state state;
+ size_t len;
u32 abort_code, remote_abort = 0;
int ret;
@@ -515,10 +518,11 @@ static void afs_deliver_to_call(struct afs_call *call)
state == AFS_CALL_SV_AWAIT_ACK
) {
if (state == AFS_CALL_SV_AWAIT_ACK) {
+ len = 0;
iov_iter_kvec(&call->def_iter, READ, NULL, 0, 0);
ret = rxrpc_kernel_recv_data(call->net->socket,
call->rxcall, &call->def_iter,
- false, &remote_abort,
+ &len, false, &remote_abort,
&call->service_id);
trace_afs_receive_data(call, &call->def_iter, false, ret);
@@ -926,10 +930,11 @@ int afs_extract_data(struct afs_call *call, bool want_more)
u32 remote_abort = 0;
int ret;
- _enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
+ _enter("{%s,%zu,%zu},%d",
+ call->type->name, call->iov_len, iov_iter_count(iter), want_more);
ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
- want_more, &remote_abort,
+ &call->iov_len, want_more, &remote_abort,
&call->service_id);
if (ret == 0 || ret == -EAGAIN)
return ret;
diff --git a/fs/afs/yfsclient.c b/fs/afs/yfsclient.c
index 7f419f8bb943..1164f48e308d 100644
--- a/fs/afs/yfsclient.c
+++ b/fs/afs/yfsclient.c
@@ -442,8 +442,9 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call)
unsigned int size;
int ret;
- _enter("{%u,%zu/%llu}",
- call->unmarshall, iov_iter_count(call->iter), req->actual_len);
+ _enter("{%u,%zu, %zu/%llu}",
+ call->unmarshall, call->iov_len, iov_iter_count(call->iter),
+ req->actual_len);
switch (call->unmarshall) {
case 0:
@@ -475,6 +476,7 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call)
size = PAGE_SIZE - req->offset;
else
size = req->remain;
+ call->iov_len = size;
call->bvec[0].bv_len = size;
call->bvec[0].bv_offset = req->offset;
call->bvec[0].bv_page = req->pages[req->index];
diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h
index 04e97bab6f28..0f7d13547b77 100644
--- a/include/net/af_rxrpc.h
+++ b/include/net/af_rxrpc.h
@@ -53,7 +53,7 @@ int rxrpc_kernel_send_data(struct socket *, struct rxrpc_call *,
struct msghdr *, size_t,
rxrpc_notify_end_tx_t);
int rxrpc_kernel_recv_data(struct socket *, struct rxrpc_call *,
- struct iov_iter *, bool, u32 *, u16 *);
+ struct iov_iter *, size_t *, bool, u32 *, u16 *);
bool rxrpc_kernel_abort_call(struct socket *, struct rxrpc_call *,
u32, int, const char *);
void rxrpc_kernel_end_call(struct socket *, struct rxrpc_call *);
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index 8578c39ec839..802b712f3d79 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -624,6 +624,7 @@ int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
* @sock: The socket that the call exists on
* @call: The call to send data through
* @iter: The buffer to receive into
+ * @_len: The amount of data we want to receive (decreased on return)
* @want_more: True if more data is expected to be read
* @_abort: Where the abort code is stored if -ECONNABORTED is returned
* @_service: Where to store the actual service ID (may be upgraded)
@@ -639,7 +640,7 @@ int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
* *_abort should also be initialised to 0.
*/
int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
- struct iov_iter *iter,
+ struct iov_iter *iter, size_t *_len,
bool want_more, u32 *_abort, u16 *_service)
{
size_t offset = 0;
@@ -647,7 +648,7 @@ int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
_enter("{%d,%s},%zu,%d",
call->debug_id, rxrpc_call_states[call->state],
- iov_iter_count(iter), want_more);
+ *_len, want_more);
ASSERTCMP(call->state, !=, RXRPC_CALL_SERVER_ACCEPTING);
@@ -658,8 +659,8 @@ int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
case RXRPC_CALL_SERVER_RECV_REQUEST:
case RXRPC_CALL_SERVER_ACK_REQUEST:
ret = rxrpc_recvmsg_data(sock, call, NULL, iter,
- iov_iter_count(iter), 0,
- &offset);
+ *_len, 0, &offset);
+ *_len -= offset;
if (ret < 0)
goto out;