block: Use bio_get_user_pages() for __bio_map_user_iov()iov_iter

XXX: block pc bios need to be split by the lower layers

1 files changed, 4 insertions, 61 deletions

diff --git a/fs/bio.c b/fs/bio.c
index 548fb99a36af..7dfded8d5be8 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -1304,14 +1304,10 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
 				      const struct iov_iter *iter,
 				      int write_to_vm, gfp_t gfp_mask)
 {
-	int j;
+	ssize_t ret;
 	size_t nr_pages;
-	struct page **pages;
 	struct bio *bio;
-	int cur_page = 0;
-	int ret, offset;
 	struct iov_iter i;
-	struct iovec iov;
 
 	if (iov_seg_start_alignment(iter) & queue_dma_alignment(q))
 		return ERR_PTR(-EINVAL);
@@ -1324,57 +1320,11 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
 	if (!bio)
 		return ERR_PTR(-ENOMEM);
 
-	ret = -ENOMEM;
-	pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask);
-	if (!pages)
+	i = *iter;
+	ret = bio_get_user_pages(bio, &i, write_to_vm);
+	if (ret < 0)
 		goto out;
 
-	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;
-		const int local_nr_pages = end - start;
-		const int page_limit = cur_page + local_nr_pages;
-
-		ret = get_user_pages_fast(uaddr, local_nr_pages,
-				write_to_vm, &pages[cur_page]);
-		if (ret < local_nr_pages) {
-			ret = -EFAULT;
-			goto out_unmap;
-		}
-
-		offset = uaddr & ~PAGE_MASK;
-		for (j = cur_page; j < page_limit; j++) {
-			unsigned int bytes = PAGE_SIZE - offset;
-
-			if (len <= 0)
-				break;
-			
-			if (bytes > len)
-				bytes = len;
-
-			/*
-			 * sorry...
-			 */
-			if (bio_add_pc_page(q, bio, pages[j], bytes, offset) <
-					    bytes)
-				break;
-
-			len -= bytes;
-			offset = 0;
-		}
-
-		cur_page = j;
-		/*
-		 * release the pages we didn't map into the bio, if any
-		 */
-		while (j < page_limit)
-			page_cache_release(pages[j++]);
-	}
-
-	kfree(pages);
-
 	/*
 	 * set data direction, and check if mapped pages need bouncing
 	 */
@@ -1385,14 +1335,7 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
 	bio->bi_flags |= (1 << BIO_USER_MAPPED);
 	return bio;
 
- out_unmap:
-	for (j = 0; j < nr_pages; j++) {
-		if(!pages[j])
-			break;
-		page_cache_release(pages[j]);
-	}
  out:
-	kfree(pages);
 	bio_put(bio);
 	return ERR_PTR(ret);
 }