iov_iter.c: get rid of bvec_copy_page_{to,from}_iter()

Just have copy_page_{to,from}_iter() fall back to kmap_atomic +
copy_{to,from}_iter() + kunmap_atomic() in ITER_BVEC case.  As
the matter of fact, that's what we want to do for any iov_iter
kind that isn't blocking - e.g. ITER_KVEC will also go that way
once we recognize it on iov_iter.c primitives level

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index 39ad713..17b7144 100644 (file)
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -486,30 +486,33 @@ static size_t copy_from_iter_bvec(void *to, size_t bytes, struct iov_iter *i)
        return wanted;
 }
 
-static size_t copy_page_to_iter_bvec(struct page *page, size_t offset,
-                                       size_t bytes, struct iov_iter *i)
+size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
 {
-       void *kaddr = kmap_atomic(page);
-       size_t wanted = copy_to_iter_bvec(kaddr + offset, bytes, i);
-       kunmap_atomic(kaddr);
-       return wanted;
+       if (i->type & ITER_BVEC)
+               return copy_to_iter_bvec(addr, bytes, i);
+       else
+               return copy_to_iter_iovec(addr, bytes, i);
 }
+EXPORT_SYMBOL(copy_to_iter);
 
-static size_t copy_page_from_iter_bvec(struct page *page, size_t offset,
-                                       size_t bytes, struct iov_iter *i)
+size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
 {
-       void *kaddr = kmap_atomic(page);
-       size_t wanted = copy_from_iter_bvec(kaddr + offset, bytes, i);
-       kunmap_atomic(kaddr);
-       return wanted;
+       if (i->type & ITER_BVEC)
+               return copy_from_iter_bvec(addr, bytes, i);
+       else
+               return copy_from_iter_iovec(addr, bytes, i);
 }
+EXPORT_SYMBOL(copy_from_iter);
 
 size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
                         struct iov_iter *i)
 {
-       if (i->type & ITER_BVEC)
-               return copy_page_to_iter_bvec(page, offset, bytes, i);
-       else
+       if (i->type & (ITER_BVEC|ITER_KVEC)) {
+               void *kaddr = kmap_atomic(page);
+               size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
+               kunmap_atomic(kaddr);
+               return wanted;
+       } else
                return copy_page_to_iter_iovec(page, offset, bytes, i);
 }
 EXPORT_SYMBOL(copy_page_to_iter);
@@ -517,31 +520,16 @@ EXPORT_SYMBOL(copy_page_to_iter);
 size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
                         struct iov_iter *i)
 {
-       if (i->type & ITER_BVEC)
-               return copy_page_from_iter_bvec(page, offset, bytes, i);
-       else
+       if (i->type & ITER_BVEC) {
+               void *kaddr = kmap_atomic(page);
+               size_t wanted = copy_from_iter(kaddr + offset, bytes, i);
+               kunmap_atomic(kaddr);
+               return wanted;
+       } else
                return copy_page_from_iter_iovec(page, offset, bytes, i);
 }
 EXPORT_SYMBOL(copy_page_from_iter);
 
-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);
-}
-EXPORT_SYMBOL(copy_to_iter);
-
-size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
-{
-       if (i->type & ITER_BVEC)
-               return copy_from_iter_bvec(addr, bytes, i);
-       else
-               return copy_from_iter_iovec(addr, bytes, i);
-}
-EXPORT_SYMBOL(copy_from_iter);
-
 size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
 {
        if (unlikely(bytes > i->count))