[PATCH v2 17/17] rds: switch rds_message_copy_from_user() to iov_iter

From: Al Viro
Date: Tue Nov 25 2014 - 09:03:07 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
net/rds/message.c | 42 ++++++++++++------------------------------
net/rds/rds.h | 3 +--
net/rds/send.c | 4 +++-
3 files changed, 16 insertions(+), 33 deletions(-)

diff --git a/net/rds/message.c b/net/rds/message.c
index 7a546e0..ff22022 100644
--- a/net/rds/message.c
+++ b/net/rds/message.c
@@ -264,64 +264,46 @@ struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned in
return rm;
}

-int rds_message_copy_from_user(struct rds_message *rm, struct iovec *first_iov,
- size_t total_len)
+int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from)
{
unsigned long to_copy;
- unsigned long iov_off;
unsigned long sg_off;
- struct iovec *iov;
struct scatterlist *sg;
int ret = 0;

- rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
+ rm->m_inc.i_hdr.h_len = cpu_to_be32(iov_iter_count(from));

/*
* now allocate and copy in the data payload.
*/
sg = rm->data.op_sg;
- iov = first_iov;
- iov_off = 0;
sg_off = 0; /* Dear gcc, sg->page will be null from kzalloc. */

- while (total_len) {
+ while (iov_iter_count(from)) {
if (!sg_page(sg)) {
- ret = rds_page_remainder_alloc(sg, total_len,
+ ret = rds_page_remainder_alloc(sg, iov_iter_count(from),
GFP_HIGHUSER);
if (ret)
- goto out;
+ return ret;
rm->data.op_nents++;
sg_off = 0;
}

- while (iov_off == iov->iov_len) {
- iov_off = 0;
- iov++;
- }
-
- to_copy = min(iov->iov_len - iov_off, sg->length - sg_off);
- to_copy = min_t(size_t, to_copy, total_len);
-
- rdsdebug("copying %lu bytes from user iov [%p, %zu] + %lu to "
- "sg [%p, %u, %u] + %lu\n",
- to_copy, iov->iov_base, iov->iov_len, iov_off,
- (void *)sg_page(sg), sg->offset, sg->length, sg_off);
+ to_copy = min_t(unsigned long, iov_iter_count(from),
+ sg->length - sg_off);

- ret = rds_page_copy_from_user(sg_page(sg), sg->offset + sg_off,
- iov->iov_base + iov_off,
- to_copy);
- if (ret)
- goto out;
+ rds_stats_add(s_copy_from_user, to_copy);
+ ret = copy_page_from_iter(sg_page(sg), sg->offset + sg_off,
+ to_copy, from);
+ if (ret != to_copy)
+ return -EFAULT;

- iov_off += to_copy;
- total_len -= to_copy;
sg_off += to_copy;

if (sg_off == sg->length)
sg++;
}

-out:
return ret;
}

diff --git a/net/rds/rds.h b/net/rds/rds.h
index b22dad9..c2a5eef 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -656,8 +656,7 @@ rds_conn_connecting(struct rds_connection *conn)
/* message.c */
struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp);
struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents);
-int rds_message_copy_from_user(struct rds_message *rm, struct iovec *first_iov,
- size_t total_len);
+int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from);
struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len);
void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
__be16 dport, u64 seq);
diff --git a/net/rds/send.c b/net/rds/send.c
index 0a64541..4de62ea 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -934,7 +934,9 @@ int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
int queued = 0, allocated_mr = 0;
int nonblock = msg->msg_flags & MSG_DONTWAIT;
long timeo = sock_sndtimeo(sk, nonblock);
+ struct iov_iter from;

+ iov_iter_init(&from, WRITE, msg->msg_iov, msg->msg_iovlen, payload_len);
/* Mirror Linux UDP mirror of BSD error message compatibility */
/* XXX: Perhaps MSG_MORE someday */
if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT)) {
@@ -982,7 +984,7 @@ int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
ret = -ENOMEM;
goto out;
}
- ret = rds_message_copy_from_user(rm, msg->msg_iov, payload_len);
+ ret = rds_message_copy_from_user(rm, &from);
if (ret)
goto out;
}
--
1.7.10.4

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