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Commit 0e4c0ee5 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'for-davem' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

parents ea6b1720 32786821

include/linux/uio.h

+5 −1
Original line number Diff line number Diff line
@@ -39,7 +39,10 @@ struct iov_iter { 
	};

	union {

		unsigned long nr_segs;

		struct {

			int idx;

			int start_idx;

		};

	};

};
@@ -81,6 +84,7 @@ unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to); 
size_t iov_iter_copy_from_user_atomic(struct page *page,

		struct iov_iter *i, unsigned long offset, size_t bytes);

void iov_iter_advance(struct iov_iter *i, size_t bytes);

void iov_iter_revert(struct iov_iter *i, size_t bytes);

int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);

size_t iov_iter_single_seg_count(const struct iov_iter *i);

size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,

lib/iov_iter.c

+63 −0
Original line number Diff line number Diff line
@@ -786,6 +786,68 @@ void iov_iter_advance(struct iov_iter *i, size_t size) 
}

EXPORT_SYMBOL(iov_iter_advance);



void iov_iter_revert(struct iov_iter *i, size_t unroll)

{

	if (!unroll)

		return;

	i->count += unroll;

	if (unlikely(i->type & ITER_PIPE)) {

		struct pipe_inode_info *pipe = i->pipe;

		int idx = i->idx;

		size_t off = i->iov_offset;

		while (1) {

			size_t n = off - pipe->bufs[idx].offset;

			if (unroll < n) {

				off -= (n - unroll);

				break;

			}

			unroll -= n;

			if (!unroll && idx == i->start_idx) {

				off = 0;

				break;

			}

			if (!idx--)

				idx = pipe->buffers - 1;

			off = pipe->bufs[idx].offset + pipe->bufs[idx].len;

		}

		i->iov_offset = off;

		i->idx = idx;

		pipe_truncate(i);

		return;

	}

	if (unroll <= i->iov_offset) {

		i->iov_offset -= unroll;

		return;

	}

	unroll -= i->iov_offset;

	if (i->type & ITER_BVEC) {

		const struct bio_vec *bvec = i->bvec;

		while (1) {

			size_t n = (--bvec)->bv_len;

			i->nr_segs++;

			if (unroll <= n) {

				i->bvec = bvec;

				i->iov_offset = n - unroll;

				return;

			}

			unroll -= n;

		}

	} else { /* same logics for iovec and kvec */

		const struct iovec *iov = i->iov;

		while (1) {

			size_t n = (--iov)->iov_len;

			i->nr_segs++;

			if (unroll <= n) {

				i->iov = iov;

				i->iov_offset = n - unroll;

				return;

			}

			unroll -= n;

		}

	}

}

EXPORT_SYMBOL(iov_iter_revert);



/*

 * Return the count of just the current iov_iter segment.

 */
@@ -839,6 +901,7 @@ void iov_iter_pipe(struct iov_iter *i, int direction, 
	i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);

	i->iov_offset = 0;

	i->count = count;

	i->start_idx = i->idx;

}

EXPORT_SYMBOL(iov_iter_pipe);

net/core/datagram.c

+14 −9
Original line number Diff line number Diff line
@@ -398,7 +398,7 @@ 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;

	int i, copy = start - offset, start_off = offset, n;

	struct sk_buff *frag_iter;



	trace_skb_copy_datagram_iovec(skb, len);
@@ -407,11 +407,12 @@ int skb_copy_datagram_iter(const struct sk_buff *skb, int offset, 
	if (copy > 0) {

		if (copy > len)

			copy = len;

		if (copy_to_iter(skb->data + offset, copy, to) != copy)

		n = copy_to_iter(skb->data + offset, copy, to);

		offset += n;

		if (n != copy)

			goto short_copy;

		if ((len -= copy) == 0)

			return 0;

		offset += copy;

	}



	/* Copy paged appendix. Hmm... why does this look so complicated? */
@@ -425,13 +426,14 @@ int skb_copy_datagram_iter(const struct sk_buff *skb, int offset, 
		if ((copy = end - offset) > 0) {

			if (copy > len)

				copy = len;

			if (copy_page_to_iter(skb_frag_page(frag),

			n = copy_page_to_iter(skb_frag_page(frag),

					      frag->page_offset + offset -

					      start, copy, to) != copy)

					      start, copy, to);

			offset += n;

			if (n != copy)

				goto short_copy;

			if (!(len -= copy))

				return 0;

			offset += copy;

		}

		start = end;

	}
@@ -463,6 +465,7 @@ int skb_copy_datagram_iter(const struct sk_buff *skb, int offset, 
	 */



fault:

	iov_iter_revert(to, offset - start_off);

	return -EFAULT;



short_copy:
@@ -613,7 +616,7 @@ static int skb_copy_and_csum_datagram(const struct sk_buff *skb, int offset, 
				      __wsum *csump)

{

	int start = skb_headlen(skb);

	int i, copy = start - offset;

	int i, copy = start - offset, start_off = offset;

	struct sk_buff *frag_iter;

	int pos = 0;

	int n;
@@ -623,11 +626,11 @@ static int skb_copy_and_csum_datagram(const struct sk_buff *skb, int offset, 
		if (copy > len)

			copy = len;

		n = csum_and_copy_to_iter(skb->data + offset, copy, csump, to);

		offset += n;

		if (n != copy)

			goto fault;

		if ((len -= copy) == 0)

			return 0;

		offset += copy;

		pos = copy;

	}
@@ -649,12 +652,12 @@ static int skb_copy_and_csum_datagram(const struct sk_buff *skb, int offset, 
						  offset - start, copy,

						  &csum2, to);

			kunmap(page);

			offset += n;

			if (n != copy)

				goto fault;

			*csump = csum_block_add(*csump, csum2, pos);

			if (!(len -= copy))

				return 0;

			offset += copy;

			pos += copy;

		}

		start = end;
@@ -687,6 +690,7 @@ static int skb_copy_and_csum_datagram(const struct sk_buff *skb, int offset, 
		return 0;



fault:

	iov_iter_revert(to, offset - start_off);

	return -EFAULT;

}
@@ -771,6 +775,7 @@ int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, 
	}

	return 0;

csum_error:

	iov_iter_revert(&msg->msg_iter, chunk);

	return -EINVAL;

fault:

	return -EFAULT;