Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753187AbaKEDlt (ORCPT ); Tue, 4 Nov 2014 22:41:49 -0500 Received: from helcar.apana.org.au ([209.40.204.226]:44433 "EHLO helcar.apana.org.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752108AbaKEDlq (ORCPT ); Tue, 4 Nov 2014 22:41:46 -0500 Date: Wed, 5 Nov 2014 11:41:36 +0800 From: Herbert Xu To: YOSHIFUJI Hideaki Cc: viro@zeniv.linux.org.uk, davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bcrl@kvack.org, hideaki.yoshifuji@miraclelinux.com Subject: Re: [PATCH 2/4] tun: Use iovec iterators Message-ID: <20141105034136.GA19761@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5459902C.1010102@miraclelinux.com> Organization: Core X-Newsgroups: apana.lists.os.linux.kernel,apana.lists.os.linux.netdev User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org YOSHIFUJI Hideaki wrote: >> >> - if (len < skb->len + vlan_hlen + vnet_hdr_sz) { >> + if (iov_iter_count(iter) < total) { > > I guess this should be: sizeof(pi) + total Good catch! Here is a third update: tun: Use iovec iterators This patch removes the use of skb_copy_datagram_const_iovec in favour of the iovec iterator-based skb_copy_datagram_iter. Signed-off-by: Herbert Xu diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 9dd3746..b4ac4d5 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -71,6 +71,7 @@ #include #include #include +#include #include @@ -1230,11 +1231,11 @@ static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv, 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 @@ static ssize_t tun_put_user(struct tun_struct *tun, 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)) 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 @@ static ssize_t tun_put_user(struct tun_struct *tun, 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)) 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 @@ static ssize_t tun_put_user(struct tun_struct *tun, 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 || !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 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile, /* 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 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, 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 @@ static int tun_recvmsg(struct kiocb *iocb, struct socket *sock, 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; Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/