iov_iter.c: convert copy_to_iter() to iterate_and_advance
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index 791429d..6666544 100644
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -97,51 +97,6 @@
i->iov_offset = skip; \
}
-static size_t copy_to_iter_iovec(void *from, size_t bytes, struct iov_iter *i)
-{
- size_t skip, copy, left, wanted;
- const struct iovec *iov;
- char __user *buf;
-
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
- wanted = bytes;
- iov = i->iov;
- skip = i->iov_offset;
- buf = iov->iov_base + skip;
- copy = min(bytes, iov->iov_len - skip);
-
- left = __copy_to_user(buf, from, copy);
- copy -= left;
- skip += copy;
- from += copy;
- bytes -= copy;
- while (unlikely(!left && bytes)) {
- iov++;
- buf = iov->iov_base;
- copy = min(bytes, iov->iov_len);
- left = __copy_to_user(buf, from, copy);
- copy -= left;
- skip = copy;
- from += copy;
- bytes -= copy;
- }
-
- if (skip == iov->iov_len) {
- iov++;
- skip = 0;
- }
- i->count -= wanted - bytes;
- i->nr_segs -= iov - i->iov;
- i->iov = iov;
- i->iov_offset = skip;
- return wanted - bytes;
-}
-
static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
@@ -360,51 +315,23 @@
kunmap_atomic(addr);
}
-static size_t copy_to_iter_bvec(void *from, size_t bytes, struct iov_iter *i)
+size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
{
- size_t skip, copy, wanted;
- const struct bio_vec *bvec;
-
+ char *from = addr;
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);
+ 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_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;
- }
- 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)
-{
- if (i->type & ITER_BVEC)
- return copy_to_iter_bvec(addr, bytes, i);
- else
- return copy_to_iter_iovec(addr, bytes, i);
+ return bytes;
}
EXPORT_SYMBOL(copy_to_iter);