iov_iter.c: convert iov_iter_npages() to iterate_all_kinds

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

diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index e91bf0a..bc666e7 100644 (file)
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -493,32 +493,6 @@ static ssize_t get_pages_alloc_iovec(struct iov_iter *i,
        return (res == n ? len : res * PAGE_SIZE) - *start;
 }
 
-static int iov_iter_npages_iovec(const struct iov_iter *i, int maxpages)
-{
-       size_t offset = i->iov_offset;
-       size_t size = i->count;
-       const struct iovec *iov = i->iov;
-       int npages = 0;
-       int n;
-
-       for (n = 0; size && n < i->nr_segs; n++, iov++) {
-               unsigned long addr = (unsigned long)iov->iov_base + offset;
-               size_t len = iov->iov_len - offset;
-               offset = 0;
-               if (unlikely(!len))     /* empty segment */
-                       continue;
-               if (len > size)
-                       len = size;
-               npages += (addr + len + PAGE_SIZE - 1) / PAGE_SIZE
-                         - addr / PAGE_SIZE;
-               if (npages >= maxpages) /* don't bother going further */
-                       return maxpages;
-               size -= len;
-               offset = 0;
-       }
-       return min(npages, maxpages);
-}
-
 static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len)
 {
        char *from = kmap_atomic(page);
@@ -715,30 +689,6 @@ static ssize_t get_pages_alloc_bvec(struct iov_iter *i,
        return len;
 }
 
-static int iov_iter_npages_bvec(const struct iov_iter *i, int maxpages)
-{
-       size_t offset = i->iov_offset;
-       size_t size = i->count;
-       const struct bio_vec *bvec = i->bvec;
-       int npages = 0;
-       int n;
-
-       for (n = 0; size && n < i->nr_segs; n++, bvec++) {
-               size_t len = bvec->bv_len - offset;
-               offset = 0;
-               if (unlikely(!len))     /* empty segment */
-                       continue;
-               if (len > size)
-                       len = size;
-               npages++;
-               if (npages >= maxpages) /* don't bother going further */
-                       return maxpages;
-               size -= len;
-               offset = 0;
-       }
-       return min(npages, maxpages);
-}
-
 size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
                         struct iov_iter *i)
 {
@@ -862,9 +812,24 @@ EXPORT_SYMBOL(iov_iter_get_pages_alloc);
 
 int iov_iter_npages(const struct iov_iter *i, int maxpages)
 {
-       if (i->type & ITER_BVEC)
-               return iov_iter_npages_bvec(i, maxpages);
-       else
-               return iov_iter_npages_iovec(i, maxpages);
+       size_t size = i->count;
+       int npages = 0;
+
+       if (!size)
+               return 0;
+
+       iterate_all_kinds(i, size, v, ({
+               unsigned long p = (unsigned long)v.iov_base;
+               npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
+                       - p / PAGE_SIZE;
+               if (npages >= maxpages)
+                       return maxpages;
+       0;}),({
+               npages++;
+               if (npages >= maxpages)
+                       return maxpages;
+       })
+       )
+       return npages;
 }
 EXPORT_SYMBOL(iov_iter_npages);