Merge branch 'iov_iter'
Herbert Xu says:
====================
Replace skb_copy_datagram_const_iovec with iterator version
This patch series adds the helper skb_copy_datagram_iter, which
is meant to replace both skb_copy_datagram_iovec and its evil
twin skb_copy_datagram_const_iovec.
It then converts tun and macvtap over to the new helper and finally
removes skb_copy_datagram_const_iovec which is only used by tun
and macvtap.
The copy_to_iter return value issue pointed out by Al has now been
fixed.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 880cc09..cea99d4 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -15,6 +15,7 @@
#include <linux/cdev.h>
#include <linux/idr.h>
#include <linux/fs.h>
+#include <linux/uio.h>
#include <net/ipv6.h>
#include <net/net_namespace.h>
@@ -778,31 +779,29 @@
/* Put packet to the user space buffer */
static ssize_t macvtap_put_user(struct macvtap_queue *q,
const struct sk_buff *skb,
- const struct iovec *iv, int len)
+ struct iov_iter *iter)
{
int ret;
int vnet_hdr_len = 0;
int vlan_offset = 0;
- int copied, total;
+ int total;
if (q->flags & IFF_VNET_HDR) {
struct virtio_net_hdr vnet_hdr;
vnet_hdr_len = q->vnet_hdr_sz;
- if ((len -= vnet_hdr_len) < 0)
+ if (iov_iter_count(iter) < vnet_hdr_len)
return -EINVAL;
macvtap_skb_to_vnet_hdr(skb, &vnet_hdr);
- if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
+ if (copy_to_iter(&vnet_hdr, sizeof(vnet_hdr), iter) !=
+ sizeof(vnet_hdr))
return -EFAULT;
}
- total = copied = vnet_hdr_len;
+ total = vnet_hdr_len;
total += skb->len;
- if (!vlan_tx_tag_present(skb))
- len = min_t(int, skb->len, len);
- else {
- int copy;
+ if (vlan_tx_tag_present(skb)) {
struct {
__be16 h_vlan_proto;
__be16 h_vlan_TCI;
@@ -811,37 +810,33 @@
veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
- len = min_t(int, skb->len + VLAN_HLEN, len);
total += VLAN_HLEN;
- copy = min_t(int, vlan_offset, len);
- ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
- len -= copy;
- copied += copy;
- if (ret || !len)
+ ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
+ if (ret || !iov_iter_count(iter))
goto done;
- copy = min_t(int, sizeof(veth), len);
- ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);
- len -= copy;
- copied += copy;
- if (ret || !len)
+ ret = copy_to_iter(&veth, sizeof(veth), iter);
+ if (ret != sizeof(veth) || !iov_iter_count(iter))
goto done;
}
- ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);
+ ret = skb_copy_datagram_iter(skb, vlan_offset, iter,
+ skb->len - vlan_offset);
done:
return ret ? ret : total;
}
static ssize_t macvtap_do_read(struct macvtap_queue *q,
- const struct iovec *iv, unsigned long len,
+ const struct iovec *iv, unsigned long segs,
+ unsigned long len,
int noblock)
{
DEFINE_WAIT(wait);
struct sk_buff *skb;
ssize_t ret = 0;
+ struct iov_iter iter;
while (len) {
if (!noblock)
@@ -863,7 +858,8 @@
schedule();
continue;
}
- ret = macvtap_put_user(q, skb, iv, len);
+ iov_iter_init(&iter, READ, iv, segs, len);
+ ret = macvtap_put_user(q, skb, &iter);
kfree_skb(skb);
break;
}
@@ -886,7 +882,7 @@
goto out;
}
- ret = macvtap_do_read(q, iv, len, file->f_flags & O_NONBLOCK);
+ ret = macvtap_do_read(q, iv, count, len, file->f_flags & O_NONBLOCK);
ret = min_t(ssize_t, ret, len);
if (ret > 0)
iocb->ki_pos = ret;
@@ -1117,7 +1113,7 @@
int ret;
if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
return -EINVAL;
- ret = macvtap_do_read(q, m->msg_iov, total_len,
+ ret = macvtap_do_read(q, m->msg_iov, m->msg_iovlen, total_len,
flags & MSG_DONTWAIT);
if (ret > total_len) {
m->msg_flags |= MSG_TRUNC;
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 9dd3746..2ff769b 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -71,6 +71,7 @@
#include <net/rtnetlink.h>
#include <net/sock.h>
#include <linux/seq_file.h>
+#include <linux/uio.h>
#include <asm/uaccess.h>
@@ -1230,11 +1231,11 @@
static ssize_t tun_put_user(struct tun_struct *tun,
struct tun_file *tfile,
struct sk_buff *skb,
- const struct iovec *iv, int len)
+ struct iov_iter *iter)
{
struct tun_pi pi = { 0, skb->protocol };
- ssize_t total = 0;
- int vlan_offset = 0, copied;
+ ssize_t total;
+ int vlan_offset;
int vlan_hlen = 0;
int vnet_hdr_sz = 0;
@@ -1244,23 +1245,25 @@
if (tun->flags & TUN_VNET_HDR)
vnet_hdr_sz = tun->vnet_hdr_sz;
+ total = skb->len + vlan_hlen + vnet_hdr_sz;
+
if (!(tun->flags & TUN_NO_PI)) {
- if ((len -= sizeof(pi)) < 0)
+ if (iov_iter_count(iter) < sizeof(pi))
return -EINVAL;
- if (len < skb->len + vlan_hlen + vnet_hdr_sz) {
+ total += sizeof(pi);
+ if (iov_iter_count(iter) < total) {
/* Packet will be striped */
pi.flags |= TUN_PKT_STRIP;
}
- if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
+ if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
return -EFAULT;
- total += sizeof(pi);
}
if (vnet_hdr_sz) {
struct virtio_net_hdr gso = { 0 }; /* no info leak */
- if ((len -= vnet_hdr_sz) < 0)
+ if (iov_iter_count(iter) < vnet_hdr_sz)
return -EINVAL;
if (skb_is_gso(skb)) {
@@ -1299,17 +1302,12 @@
gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
} /* else everything is zero */
- if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
- sizeof(gso))))
+ if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
return -EFAULT;
- total += vnet_hdr_sz;
}
- copied = total;
- len = min_t(int, skb->len + vlan_hlen, len);
- total += skb->len + vlan_hlen;
if (vlan_hlen) {
- int copy, ret;
+ int ret;
struct {
__be16 h_vlan_proto;
__be16 h_vlan_TCI;
@@ -1320,36 +1318,32 @@
vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
- copy = min_t(int, vlan_offset, len);
- ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
- len -= copy;
- copied += copy;
- if (ret || !len)
+ ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
+ if (ret || !iov_iter_count(iter))
goto done;
- copy = min_t(int, sizeof(veth), len);
- ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);
- len -= copy;
- copied += copy;
- if (ret || !len)
+ ret = copy_to_iter(&veth, sizeof(veth), iter);
+ if (ret != sizeof(veth) || !iov_iter_count(iter))
goto done;
}
- skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);
+ skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
done:
tun->dev->stats.tx_packets++;
- tun->dev->stats.tx_bytes += len;
+ tun->dev->stats.tx_bytes += skb->len + vlan_hlen;
return total;
}
static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
- const struct iovec *iv, ssize_t len, int noblock)
+ const struct iovec *iv, unsigned long segs,
+ ssize_t len, int noblock)
{
struct sk_buff *skb;
ssize_t ret = 0;
int peeked, err, off = 0;
+ struct iov_iter iter;
tun_debug(KERN_INFO, tun, "tun_do_read\n");
@@ -1362,11 +1356,12 @@
/* Read frames from queue */
skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,
&peeked, &off, &err);
- if (skb) {
- ret = tun_put_user(tun, tfile, skb, iv, len);
- kfree_skb(skb);
- } else
- ret = err;
+ if (!skb)
+ return ret;
+
+ iov_iter_init(&iter, READ, iv, segs, len);
+ ret = tun_put_user(tun, tfile, skb, &iter);
+ kfree_skb(skb);
return ret;
}
@@ -1387,7 +1382,7 @@
goto out;
}
- ret = tun_do_read(tun, tfile, iv, len,
+ ret = tun_do_read(tun, tfile, iv, count, len,
file->f_flags & O_NONBLOCK);
ret = min_t(ssize_t, ret, len);
if (ret > 0)
@@ -1488,7 +1483,7 @@
SOL_PACKET, TUN_TX_TIMESTAMP);
goto out;
}
- ret = tun_do_read(tun, tfile, m->msg_iov, total_len,
+ ret = tun_do_read(tun, tfile, m->msg_iov, m->msg_iovlen, total_len,
flags & MSG_DONTWAIT);
if (ret > total_len) {
m->msg_flags |= MSG_TRUNC;
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 53f4f6c..103fbe8 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -150,6 +150,7 @@
struct net_device;
struct scatterlist;
struct pipe_inode_info;
+struct iov_iter;
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
struct nf_conntrack {
@@ -2650,9 +2651,8 @@
int len);
int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *frm,
int offset, size_t count);
-int skb_copy_datagram_const_iovec(const struct sk_buff *from, int offset,
- const struct iovec *to, int to_offset,
- int size);
+int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
+ struct iov_iter *to, int size);
void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb);
int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
diff --git a/net/core/datagram.c b/net/core/datagram.c
index fdbc9a8..26391a3 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -49,6 +49,7 @@
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
+#include <linux/uio.h>
#include <net/protocol.h>
#include <linux/skbuff.h>
@@ -393,34 +394,30 @@
EXPORT_SYMBOL(skb_copy_datagram_iovec);
/**
- * skb_copy_datagram_const_iovec - Copy a datagram to an iovec.
+ * skb_copy_datagram_iter - Copy a datagram to an iovec iterator.
* @skb: buffer to copy
* @offset: offset in the buffer to start copying from
- * @to: io vector to copy to
- * @to_offset: offset in the io vector to start copying to
+ * @to: iovec iterator to copy to
* @len: amount of data to copy from buffer to iovec
- *
- * Returns 0 or -EFAULT.
- * Note: the iovec is not modified during the copy.
*/
-int skb_copy_datagram_const_iovec(const struct sk_buff *skb, int offset,
- const struct iovec *to, int to_offset,
- int len)
+int skb_copy_datagram_iter(const struct sk_buff *skb, int offset,
+ struct iov_iter *to, int len)
{
int start = skb_headlen(skb);
int i, copy = start - offset;
struct sk_buff *frag_iter;
+ trace_skb_copy_datagram_iovec(skb, len);
+
/* Copy header. */
if (copy > 0) {
if (copy > len)
copy = len;
- if (memcpy_toiovecend(to, skb->data + offset, to_offset, copy))
- goto fault;
+ if (copy_to_iter(skb->data + offset, copy, to) != copy)
+ goto short_copy;
if ((len -= copy) == 0)
return 0;
offset += copy;
- to_offset += copy;
}
/* Copy paged appendix. Hmm... why does this look so complicated? */
@@ -432,22 +429,15 @@
end = start + skb_frag_size(frag);
if ((copy = end - offset) > 0) {
- int err;
- u8 *vaddr;
- struct page *page = skb_frag_page(frag);
-
if (copy > len)
copy = len;
- vaddr = kmap(page);
- err = memcpy_toiovecend(to, vaddr + frag->page_offset +
- offset - start, to_offset, copy);
- kunmap(page);
- if (err)
- goto fault;
+ if (copy_page_to_iter(skb_frag_page(frag),
+ frag->page_offset + offset -
+ start, copy, to) != copy)
+ goto short_copy;
if (!(len -= copy))
return 0;
offset += copy;
- to_offset += copy;
}
start = end;
}
@@ -461,25 +451,33 @@
if ((copy = end - offset) > 0) {
if (copy > len)
copy = len;
- if (skb_copy_datagram_const_iovec(frag_iter,
- offset - start,
- to, to_offset,
- copy))
+ if (skb_copy_datagram_iter(frag_iter, offset - start,
+ to, copy))
goto fault;
if ((len -= copy) == 0)
return 0;
offset += copy;
- to_offset += copy;
}
start = end;
}
if (!len)
return 0;
+ /* This is not really a user copy fault, but rather someone
+ * gave us a bogus length on the skb. We should probably
+ * print a warning here as it may indicate a kernel bug.
+ */
+
fault:
return -EFAULT;
+
+short_copy:
+ if (iov_iter_count(to))
+ goto fault;
+
+ return 0;
}
-EXPORT_SYMBOL(skb_copy_datagram_const_iovec);
+EXPORT_SYMBOL(skb_copy_datagram_iter);
/**
* skb_copy_datagram_from_iovec - Copy a datagram from an iovec.