From cbbd26b8b1a6af9c02e2b6523e12bd50cc765059 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 1 Nov 2016 22:09:04 -0400 Subject: [iov_iter] new primitives - copy_from_iter_full() and friends copy_from_iter_full(), copy_from_iter_full_nocache() and csum_and_copy_from_iter_full() - counterparts of copy_from_iter() et.al., advancing iterator only in case of successful full copy and returning whether it had been successful or not. Convert some obvious users. *NOTE* - do not blindly assume that something is a good candidate for those unless you are sure that not advancing iov_iter in failure case is the right thing in this case. Anything that does short read/short write kind of stuff (or is in a loop, etc.) is unlikely to be a good one. Signed-off-by: Al Viro --- drivers/net/tun.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'drivers/net/tun.c') diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 8093e39ae263..4fa2d756548a 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1171,7 +1171,6 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, bool zerocopy = false; int err; u32 rxhash; - ssize_t n; if (!(tun->dev->flags & IFF_UP)) return -EIO; @@ -1181,8 +1180,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, return -EINVAL; len -= sizeof(pi); - n = copy_from_iter(&pi, sizeof(pi), from); - if (n != sizeof(pi)) + if (!copy_from_iter_full(&pi, sizeof(pi), from)) return -EFAULT; } @@ -1191,8 +1189,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, return -EINVAL; len -= tun->vnet_hdr_sz; - n = copy_from_iter(&gso, sizeof(gso), from); - if (n != sizeof(gso)) + if (!copy_from_iter_full(&gso, sizeof(gso), from)) return -EFAULT; if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && -- cgit v1.2.3