Commit f9152895 authored by Al Viro's avatar Al Viro
Browse files

iov_iter: reduce code duplication 



The same combination of csum_partial_copy_nocheck() with csum_add_block()
is used in a bunch of places.  Add a helper doing just that and use it.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 78e1f386

lib/iov_iter.c

+27 −27
Original line number Diff line number Diff line
@@ -560,13 +560,20 @@ static size_t copy_pipe_to_iter(const void *addr, size_t bytes, 
	return bytes;

}



static __wsum csum_and_memcpy(void *to, const void *from, size_t len,

			      __wsum sum, size_t off)

{

	__wsum next = csum_partial_copy_nocheck(from, to, len, 0);

	return csum_block_add(sum, next, off);

}



static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes,

				__wsum *csum, struct iov_iter *i)

{

	struct pipe_inode_info *pipe = i->pipe;

	size_t n, r;

	size_t off = 0;

	__wsum sum = *csum, next;

	__wsum sum = *csum;

	int idx;



	if (!sanity(i))
@@ -578,8 +585,7 @@ static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, 
	for ( ; n; idx = next_idx(idx, pipe), r = 0) {

		size_t chunk = min_t(size_t, n, PAGE_SIZE - r);

		char *p = kmap_atomic(pipe->bufs[idx].page);

		next = csum_partial_copy_nocheck(addr, p + r, chunk, 0);

		sum = csum_block_add(sum, next, off);

		sum = csum_and_memcpy(p + r, addr, chunk, sum, off);

		kunmap_atomic(p);

		i->idx = idx;

		i->iov_offset = r + chunk;
@@ -1400,17 +1406,15 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 
		err ? v.iov_len : 0;

	}), ({

		char *p = kmap_atomic(v.bv_page);

		next = csum_partial_copy_nocheck(p + v.bv_offset,

						 (to += v.bv_len) - v.bv_len,

						 v.bv_len, 0);

		sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,

				      p + v.bv_offset, v.bv_len,

				      sum, off);

		kunmap_atomic(p);

		sum = csum_block_add(sum, next, off);

		off += v.bv_len;

	}),({

		next = csum_partial_copy_nocheck(v.iov_base,

						 (to += v.iov_len) - v.iov_len,

						 v.iov_len, 0);

		sum = csum_block_add(sum, next, off);

		sum = csum_and_memcpy((to += v.iov_len) - v.iov_len,

				      v.iov_base, v.iov_len,

				      sum, off);

		off += v.iov_len;

	})

	)
@@ -1444,17 +1448,15 @@ bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, 
		0;

	}), ({

		char *p = kmap_atomic(v.bv_page);

		next = csum_partial_copy_nocheck(p + v.bv_offset,

						 (to += v.bv_len) - v.bv_len,

						 v.bv_len, 0);

		sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,

				      p + v.bv_offset, v.bv_len,

				      sum, off);

		kunmap_atomic(p);

		sum = csum_block_add(sum, next, off);

		off += v.bv_len;

	}),({

		next = csum_partial_copy_nocheck(v.iov_base,

						 (to += v.iov_len) - v.iov_len,

						 v.iov_len, 0);

		sum = csum_block_add(sum, next, off);

		sum = csum_and_memcpy((to += v.iov_len) - v.iov_len,

				      v.iov_base, v.iov_len,

				      sum, off);

		off += v.iov_len;

	})

	)
@@ -1491,17 +1493,15 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum, 
		err ? v.iov_len : 0;

	}), ({

		char *p = kmap_atomic(v.bv_page);

		next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len,

						 p + v.bv_offset,

						 v.bv_len, 0);

		sum = csum_and_memcpy(p + v.bv_offset,

				      (from += v.bv_len) - v.bv_len,

				      v.bv_len, sum, off);

		kunmap_atomic(p);

		sum = csum_block_add(sum, next, off);

		off += v.bv_len;

	}),({

		next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len,

						 v.iov_base,

						 v.iov_len, 0);

		sum = csum_block_add(sum, next, off);

		sum = csum_and_memcpy(v.iov_base,

				     (from += v.iov_len) - v.iov_len,

				     v.iov_len, sum, off);

		off += v.iov_len;

	})

	)