iov_iter.c: convert iov_iter_npages() to iterate_all_kinds

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

1 files changed, 19 insertions, 54 deletions

diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index e91bf0accc47..bc666e79b5bd 100644
--- 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);