[PATCH 16/17] rds: switch ->inc_copy_to_user() to passing iov_iter

From: Al Viro
Date: Fri Nov 21 2014 - 23:38:58 EST


instances get considerably simpler from that...

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
net/rds/ib.h | 3 +--
net/rds/ib_recv.c | 37 +++++++++++--------------------------
net/rds/iw.h | 3 +--
net/rds/iw_recv.c | 37 +++++++++++--------------------------
net/rds/message.c | 35 ++++++++---------------------------
net/rds/rds.h | 6 ++----
net/rds/recv.c | 5 +++--
net/rds/tcp.h | 3 +--
net/rds/tcp_recv.c | 38 +++++++++-----------------------------
9 files changed, 47 insertions(+), 120 deletions(-)

diff --git a/net/rds/ib.h b/net/rds/ib.h
index 7280ab8..c36d713 100644
--- a/net/rds/ib.h
+++ b/net/rds/ib.h
@@ -316,8 +316,7 @@ int rds_ib_recv_alloc_caches(struct rds_ib_connection *ic);
void rds_ib_recv_free_caches(struct rds_ib_connection *ic);
void rds_ib_recv_refill(struct rds_connection *conn, int prefill);
void rds_ib_inc_free(struct rds_incoming *inc);
-int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iovec *iov,
- size_t size);
+int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
void rds_ib_recv_cq_comp_handler(struct ib_cq *cq, void *context);
void rds_ib_recv_tasklet_fn(unsigned long data);
void rds_ib_recv_init_ring(struct rds_ib_connection *ic);
diff --git a/net/rds/ib_recv.c b/net/rds/ib_recv.c
index d67de45..1b981a4 100644
--- a/net/rds/ib_recv.c
+++ b/net/rds/ib_recv.c
@@ -472,15 +472,12 @@ static struct list_head *rds_ib_recv_cache_get(struct rds_ib_refill_cache *cache
return head;
}

-int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
- size_t size)
+int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
{
struct rds_ib_incoming *ibinc;
struct rds_page_frag *frag;
- struct iovec *iov = first_iov;
unsigned long to_copy;
unsigned long frag_off = 0;
- unsigned long iov_off = 0;
int copied = 0;
int ret;
u32 len;
@@ -489,37 +486,25 @@ int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
frag = list_entry(ibinc->ii_frags.next, struct rds_page_frag, f_item);
len = be32_to_cpu(inc->i_hdr.h_len);

- while (copied < size && copied < len) {
+ while (iov_iter_count(to) && copied < len) {
if (frag_off == RDS_FRAG_SIZE) {
frag = list_entry(frag->f_item.next,
struct rds_page_frag, f_item);
frag_off = 0;
}
- while (iov_off == iov->iov_len) {
- iov_off = 0;
- iov++;
- }
-
- to_copy = min(iov->iov_len - iov_off, RDS_FRAG_SIZE - frag_off);
- to_copy = min_t(size_t, to_copy, size - copied);
+ to_copy = min_t(unsigned long, iov_iter_count(to),
+ RDS_FRAG_SIZE - frag_off);
to_copy = min_t(unsigned long, to_copy, len - copied);

- rdsdebug("%lu bytes to user [%p, %zu] + %lu from frag "
- "[%p, %u] + %lu\n",
- to_copy, iov->iov_base, iov->iov_len, iov_off,
- sg_page(&frag->f_sg), frag->f_sg.offset, frag_off);
-
/* XXX needs + offset for multiple recvs per page */
- ret = rds_page_copy_to_user(sg_page(&frag->f_sg),
- frag->f_sg.offset + frag_off,
- iov->iov_base + iov_off,
- to_copy);
- if (ret) {
- copied = ret;
- break;
- }
+ rds_stats_add(s_copy_to_user, to_copy);
+ ret = copy_page_to_iter(sg_page(&frag->f_sg),
+ frag->f_sg.offset + frag_off,
+ to_copy,
+ to);
+ if (ret != to_copy)
+ return -EFAULT;

- iov_off += to_copy;
frag_off += to_copy;
copied += to_copy;
}
diff --git a/net/rds/iw.h b/net/rds/iw.h
index 04ce3b1..cbe6674 100644
--- a/net/rds/iw.h
+++ b/net/rds/iw.h
@@ -325,8 +325,7 @@ int rds_iw_recv(struct rds_connection *conn);
int rds_iw_recv_refill(struct rds_connection *conn, gfp_t kptr_gfp,
gfp_t page_gfp, int prefill);
void rds_iw_inc_free(struct rds_incoming *inc);
-int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iovec *iov,
- size_t size);
+int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
void rds_iw_recv_cq_comp_handler(struct ib_cq *cq, void *context);
void rds_iw_recv_tasklet_fn(unsigned long data);
void rds_iw_recv_init_ring(struct rds_iw_connection *ic);
diff --git a/net/rds/iw_recv.c b/net/rds/iw_recv.c
index aa8bf67..a66d179 100644
--- a/net/rds/iw_recv.c
+++ b/net/rds/iw_recv.c
@@ -303,15 +303,12 @@ void rds_iw_inc_free(struct rds_incoming *inc)
BUG_ON(atomic_read(&rds_iw_allocation) < 0);
}

-int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
- size_t size)
+int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
{
struct rds_iw_incoming *iwinc;
struct rds_page_frag *frag;
- struct iovec *iov = first_iov;
unsigned long to_copy;
unsigned long frag_off = 0;
- unsigned long iov_off = 0;
int copied = 0;
int ret;
u32 len;
@@ -320,37 +317,25 @@ int rds_iw_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
frag = list_entry(iwinc->ii_frags.next, struct rds_page_frag, f_item);
len = be32_to_cpu(inc->i_hdr.h_len);

- while (copied < size && copied < len) {
+ while (iov_iter_count(to) && copied < len) {
if (frag_off == RDS_FRAG_SIZE) {
frag = list_entry(frag->f_item.next,
struct rds_page_frag, f_item);
frag_off = 0;
}
- while (iov_off == iov->iov_len) {
- iov_off = 0;
- iov++;
- }
-
- to_copy = min(iov->iov_len - iov_off, RDS_FRAG_SIZE - frag_off);
- to_copy = min_t(size_t, to_copy, size - copied);
+ to_copy = min_t(unsigned long, iov_iter_count(to),
+ RDS_FRAG_SIZE - frag_off);
to_copy = min_t(unsigned long, to_copy, len - copied);

- rdsdebug("%lu bytes to user [%p, %zu] + %lu from frag "
- "[%p, %lu] + %lu\n",
- to_copy, iov->iov_base, iov->iov_len, iov_off,
- frag->f_page, frag->f_offset, frag_off);
-
/* XXX needs + offset for multiple recvs per page */
- ret = rds_page_copy_to_user(frag->f_page,
- frag->f_offset + frag_off,
- iov->iov_base + iov_off,
- to_copy);
- if (ret) {
- copied = ret;
- break;
- }
+ rds_stats_add(s_copy_to_user, to_copy);
+ ret = copy_page_to_iter(frag->f_page,
+ frag->f_offset + frag_off,
+ to_copy,
+ to);
+ if (ret != to_copy)
+ return -EFAULT;

- iov_off += to_copy;
frag_off += to_copy;
copied += to_copy;
}
diff --git a/net/rds/message.c b/net/rds/message.c
index aba232f..7a546e0 100644
--- a/net/rds/message.c
+++ b/net/rds/message.c
@@ -325,14 +325,11 @@ out:
return ret;
}

-int rds_message_inc_copy_to_user(struct rds_incoming *inc,
- struct iovec *first_iov, size_t size)
+int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
{
struct rds_message *rm;
- struct iovec *iov;
struct scatterlist *sg;
unsigned long to_copy;
- unsigned long iov_off;
unsigned long vec_off;
int copied;
int ret;
@@ -341,36 +338,20 @@ int rds_message_inc_copy_to_user(struct rds_incoming *inc,
rm = container_of(inc, struct rds_message, m_inc);
len = be32_to_cpu(rm->m_inc.i_hdr.h_len);

- iov = first_iov;
- iov_off = 0;
sg = rm->data.op_sg;
vec_off = 0;
copied = 0;

- while (copied < size && copied < len) {
- while (iov_off == iov->iov_len) {
- iov_off = 0;
- iov++;
- }
-
- to_copy = min(iov->iov_len - iov_off, sg->length - vec_off);
- to_copy = min_t(size_t, to_copy, size - copied);
+ while (iov_iter_count(to) && copied < len) {
+ to_copy = min(iov_iter_count(to), sg->length - vec_off);
to_copy = min_t(unsigned long, to_copy, len - copied);

- rdsdebug("copying %lu bytes to user iov [%p, %zu] + %lu to "
- "sg [%p, %u, %u] + %lu\n",
- to_copy, iov->iov_base, iov->iov_len, iov_off,
- sg_page(sg), sg->offset, sg->length, vec_off);
-
- ret = rds_page_copy_to_user(sg_page(sg), sg->offset + vec_off,
- iov->iov_base + iov_off,
- to_copy);
- if (ret) {
- copied = ret;
- break;
- }
+ rds_stats_add(s_copy_to_user, to_copy);
+ ret = copy_page_to_iter(sg_page(sg), sg->offset + vec_off,
+ to_copy, to);
+ if (ret != to_copy)
+ return -EFAULT;

- iov_off += to_copy;
vec_off += to_copy;
copied += to_copy;

diff --git a/net/rds/rds.h b/net/rds/rds.h
index 48f8ffc..b22dad9 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -431,8 +431,7 @@ struct rds_transport {
int (*xmit_rdma)(struct rds_connection *conn, struct rm_rdma_op *op);
int (*xmit_atomic)(struct rds_connection *conn, struct rm_atomic_op *op);
int (*recv)(struct rds_connection *conn);
- int (*inc_copy_to_user)(struct rds_incoming *inc, struct iovec *iov,
- size_t size);
+ int (*inc_copy_to_user)(struct rds_incoming *inc, struct iov_iter *to);
void (*inc_free)(struct rds_incoming *inc);

int (*cm_handle_connect)(struct rdma_cm_id *cm_id,
@@ -667,8 +666,7 @@ int rds_message_add_extension(struct rds_header *hdr,
int rds_message_next_extension(struct rds_header *hdr,
unsigned int *pos, void *buf, unsigned int *buflen);
int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset);
-int rds_message_inc_copy_to_user(struct rds_incoming *inc,
- struct iovec *first_iov, size_t size);
+int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
void rds_message_inc_free(struct rds_incoming *inc);
void rds_message_addref(struct rds_message *rm);
void rds_message_put(struct rds_message *rm);
diff --git a/net/rds/recv.c b/net/rds/recv.c
index bd82522..47d7b10 100644
--- a/net/rds/recv.c
+++ b/net/rds/recv.c
@@ -404,6 +404,7 @@ int rds_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
int ret = 0, nonblock = msg_flags & MSG_DONTWAIT;
DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
struct rds_incoming *inc = NULL;
+ struct iov_iter to;

/* udp_recvmsg()->sock_recvtimeo() gets away without locking too.. */
timeo = sock_rcvtimeo(sk, nonblock);
@@ -449,8 +450,8 @@ int rds_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
rdsdebug("copying inc %p from %pI4:%u to user\n", inc,
&inc->i_conn->c_faddr,
ntohs(inc->i_hdr.h_sport));
- ret = inc->i_conn->c_trans->inc_copy_to_user(inc, msg->msg_iov,
- size);
+ iov_iter_init(&to, READ, msg->msg_iov, msg->msg_iovlen, size);
+ ret = inc->i_conn->c_trans->inc_copy_to_user(inc, &to);
if (ret < 0)
break;

diff --git a/net/rds/tcp.h b/net/rds/tcp.h
index 6563749..0dbdd37 100644
--- a/net/rds/tcp.h
+++ b/net/rds/tcp.h
@@ -69,8 +69,7 @@ void rds_tcp_recv_exit(void);
void rds_tcp_data_ready(struct sock *sk);
int rds_tcp_recv(struct rds_connection *conn);
void rds_tcp_inc_free(struct rds_incoming *inc);
-int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iovec *iov,
- size_t size);
+int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);

/* tcp_send.c */
void rds_tcp_xmit_prepare(struct rds_connection *conn);
diff --git a/net/rds/tcp_recv.c b/net/rds/tcp_recv.c
index 9ae6e0a..fbc5ef8 100644
--- a/net/rds/tcp_recv.c
+++ b/net/rds/tcp_recv.c
@@ -59,50 +59,30 @@ void rds_tcp_inc_free(struct rds_incoming *inc)
/*
* this is pretty lame, but, whatever.
*/
-int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov,
- size_t size)
+int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
{
struct rds_tcp_incoming *tinc;
- struct iovec *iov, tmp;
struct sk_buff *skb;
- unsigned long to_copy, skb_off;
int ret = 0;

- if (size == 0)
+ if (!iov_iter_count(to))
goto out;

tinc = container_of(inc, struct rds_tcp_incoming, ti_inc);
- iov = first_iov;
- tmp = *iov;

skb_queue_walk(&tinc->ti_skb_list, skb) {
- skb_off = 0;
- while (skb_off < skb->len) {
- while (tmp.iov_len == 0) {
- iov++;
- tmp = *iov;
- }
-
- to_copy = min(tmp.iov_len, size);
+ unsigned long to_copy, skb_off;
+ for (skb_off = 0; skb_off < skb->len; skb_off += to_copy) {
+ to_copy = iov_iter_count(to);
to_copy = min(to_copy, skb->len - skb_off);

- rdsdebug("ret %d size %zu skb %p skb_off %lu "
- "skblen %d iov_base %p iov_len %zu cpy %lu\n",
- ret, size, skb, skb_off, skb->len,
- tmp.iov_base, tmp.iov_len, to_copy);
-
- /* modifies tmp as it copies */
- if (skb_copy_datagram_iovec(skb, skb_off, &tmp,
- to_copy)) {
- ret = -EFAULT;
- goto out;
- }
+ if (skb_copy_datagram_iter(skb, skb_off, to, to_copy))
+ return -EFAULT;

rds_stats_add(s_copy_to_user, to_copy);
- size -= to_copy;
ret += to_copy;
- skb_off += to_copy;
- if (size == 0)
+
+ if (!iov_iter_count(to))
goto out;
}
}
--
1.7.10.4

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