Commit 2495bdcc authored by Al Viro's avatar Al Viro
Browse files

iov_iter: clean csum_and_copy_...() primitives up a bit 



1) kmap_atomic() is not needed here, kmap_local_page() is enough.
2) No need to make sum = csum_block_add(sum, next, off); conditional
upon next != 0 - adding 0 is a no-op as far as csum_block_add()
is concerned.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 55ca375c

lib/iov_iter.c

+4 −6
Original line number Diff line number Diff line
@@ -600,9 +600,9 @@ static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, 
		return 0;

	do {

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

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

		char *p = kmap_local_page(pipe->bufs[i_head & p_mask].page);

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

		kunmap_atomic(p);

		kunmap_local(p);

		i->head = i_head;

		i->iov_offset = r + chunk;

		n -= chunk;
@@ -1665,7 +1665,6 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 
	}

	iterate_and_advance(i, bytes, base, len, off, ({

		next = csum_and_copy_from_user(base, addr + off, len);

		if (next)

		sum = csum_block_add(sum, next, off);

		next ? 0 : len;

	}), ({
@@ -1693,7 +1692,6 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate, 
	}

	iterate_and_advance(i, bytes, base, len, off, ({

		next = csum_and_copy_to_user(addr + off, base, len);

		if (next)

		sum = csum_block_add(sum, next, off);

		next ? 0 : len;

	}), ({