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: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2018-11-27 22:32:59 -05:00
parent 78e1f38617
commit f91528955d

View File

@ -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;
})
)