[PATCH RESEND] bio: switch to iov_iter_{npages,alignment}

[Ming Lin <mlin@kernel.org>]

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lin <mlin@kernel.org>
---
 block/bio.c | 45 +++++++--------------------------------------
 1 file changed, 7 insertions(+), 38 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index ae31cdb..e6bd9c2 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1129,29 +1129,14 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
 	struct bio_map_data *bmd;
 	struct page *page;
 	struct bio *bio;
-	int i, ret;
+	int uninitialized_var(i), ret;
 	int nr_pages = 0;
 	unsigned int len = iter->count;
 	unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0;
 
-	for (i = 0; i < iter->nr_segs; i++) {
-		unsigned long uaddr;
-		unsigned long end;
-		unsigned long start;
-
-		uaddr = (unsigned long) iter->iov[i].iov_base;
-		end = (uaddr + iter->iov[i].iov_len + PAGE_SIZE - 1)
-			>> PAGE_SHIFT;
-		start = uaddr >> PAGE_SHIFT;
-
-		/*
-		 * Overflow, abort
-		 */
-		if (end < start)
-			return ERR_PTR(-EINVAL);
-
-		nr_pages += end - start;
-	}
+	nr_pages = iov_iter_npages(iter, INT_MAX);
+	if (!nr_pages)
+		return ERR_PTR(-EINVAL);
 
 	if (offset)
 		nr_pages++;
@@ -1263,26 +1248,10 @@ struct bio *bio_map_user_iov(struct request_queue *q,
 	struct iov_iter i;
 	struct iovec iov;
 
-	iov_for_each(iov, i, *iter) {
-		unsigned long uaddr = (unsigned long) iov.iov_base;
-		unsigned long len = iov.iov_len;
-		unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-		unsigned long start = uaddr >> PAGE_SHIFT;
-
-		/*
-		 * Overflow, abort
-		 */
-		if (end < start)
-			return ERR_PTR(-EINVAL);
-
-		nr_pages += end - start;
-		/*
-		 * buffer must be aligned to at least hardsector size for now
-		 */
-		if (uaddr & queue_dma_alignment(q))
-			return ERR_PTR(-EINVAL);
-	}
+	if (iov_iter_alignment(iter) & queue_dma_alignment(q))
+		return ERR_PTR(-EINVAL);
 
+	nr_pages = iov_iter_npages(iter, INT_MAX);
 	if (!nr_pages)
 		return ERR_PTR(-EINVAL);
 
-- 
1.9.1