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 791429d07965e99439c21f7e88fc09098d15ba70..666654498ccf8e86b13f8f4df5ddd0227cd7548b 100644 (file)
--- 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 @@ static void memzero_page(struct page *page, size_t offset, size_t len)
        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);
-
-       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;
-}
+       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)
+       )
 
-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);