switch iov_iter_get_pages() to passing maximal number of pages

... instead of maximal size.

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

1 files changed, 8 insertions, 9 deletions

diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index 7b5dbd1517b5..ab88dc0ea1d3 100644
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -310,7 +310,7 @@ void iov_iter_init(struct iov_iter *i, int direction,
 EXPORT_SYMBOL(iov_iter_init);
 
 static ssize_t get_pages_iovec(struct iov_iter *i,
-                   struct page **pages, size_t maxsize,
+                   struct page **pages, unsigned maxpages,
                    size_t *start)
 {
         size_t offset = i->iov_offset;
@@ -323,10 +323,10 @@ static ssize_t get_pages_iovec(struct iov_iter *i,
         len = iov->iov_len - offset;
         if (len > i->count)
                 len = i->count;
-        if (len > maxsize)
-                len = maxsize;
         addr = (unsigned long)iov->iov_base + offset;
         len += *start = addr & (PAGE_SIZE - 1);
+        if (len > maxpages * PAGE_SIZE)
+                len = maxpages * PAGE_SIZE;
         addr &= ~(PAGE_SIZE - 1);
         n = (len + PAGE_SIZE - 1) / PAGE_SIZE;
         res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages);
@@ -588,15 +588,14 @@ static unsigned long alignment_bvec(const struct iov_iter *i)
 }
 
 static ssize_t get_pages_bvec(struct iov_iter *i,
-                   struct page **pages, size_t maxsize,
+                   struct page **pages, unsigned maxpages,
                    size_t *start)
 {
         const struct bio_vec *bvec = i->bvec;
         size_t len = bvec->bv_len - i->iov_offset;
         if (len > i->count)
                 len = i->count;
-        if (len > maxsize)
-                len = maxsize;
+        /* can't be more than PAGE_SIZE */
         *start = bvec->bv_offset + i->iov_offset;
 
         get_page(*pages = bvec->bv_page);
@@ -712,13 +711,13 @@ unsigned long iov_iter_alignment(const struct iov_iter *i)
 EXPORT_SYMBOL(iov_iter_alignment);
 
 ssize_t iov_iter_get_pages(struct iov_iter *i,
-                   struct page **pages, size_t maxsize,
+                   struct page **pages, unsigned maxpages,
                    size_t *start)
 {
         if (i->type & ITER_BVEC)
-                return get_pages_bvec(i, pages, maxsize, start);
+                return get_pages_bvec(i, pages, maxpages, start);
         else
-                return get_pages_iovec(i, pages, maxsize, start);
+                return get_pages_iovec(i, pages, maxpages, start);
 }
 EXPORT_SYMBOL(iov_iter_get_pages);