static size_t copy_page_to_iter_bvec(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
size_t skip, copy, wanted;
const struct bio_vec *bvec;
void *kaddr, *from;
if (unlikely(bytes > i->count))
bytes = i->count;
if (unlikely(!bytes))
return 0;
wanted = bytes;
bvec = i->bvec;
skip = i->iov_offset;
copy = min_t(size_t, bytes, bvec->bv_len - skip);
kaddr = kmap_atomic(page);
from = kaddr + offset;
memcpy_to_page(bvec->bv_page, skip + bvec->bv_offset, from, copy);
skip += copy;
from += copy;
bytes -= copy;
while (bytes) {
bvec++;
copy = min(bytes, (size_t)bvec->bv_len);
memcpy_to_page(bvec->bv_page, bvec->bv_offset, from, copy);
skip = copy;
from += copy;
bytes -= copy;
}
kunmap_atomic(kaddr);
if (skip == bvec->bv_len) {
bvec++;
skip = 0;
}
i->count -= wanted - bytes;
i->nr_segs -= bvec - i->bvec;
i->bvec = bvec;
i->iov_offset = skip;
return wanted - bytes;
}
size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
{
char *from = addr;
if (unlikely(bytes > i->count))
bytes = i->count;
if (unlikely(!bytes))
return 0;
iterate_and_advance(i, bytes, v,
__copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len,
v.iov_len),
memcpy_to_page(v.bv_page, v.bv_offset,
(from += v.bv_len) - v.bv_len, v.bv_len),
memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len)
)
return bytes;
}
