1 files changed, 645 insertions, 91 deletions

diff --git a/block/blk-map.c b/block/blk-map.c
index b0790268ed9d..71210cdb3442 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -11,90 +11,608 @@
 
 #include "blk.h"
 
-/*
- * Append a bio to a passthrough request.  Only works if the bio can be merged
- * into the request based on the driver constraints.
+struct bio_map_data {
+	bool is_our_pages : 1;
+	bool is_null_mapped : 1;
+	struct iov_iter iter;
+	struct iovec iov[];
+};
+
+static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data,
+					       gfp_t gfp_mask)
+{
+	struct bio_map_data *bmd;
+
+	if (data->nr_segs > UIO_MAXIOV)
+		return NULL;
+
+	bmd = kmalloc(struct_size(bmd, iov, data->nr_segs), gfp_mask);
+	if (!bmd)
+		return NULL;
+	bmd->iter = *data;
+	if (iter_is_iovec(data)) {
+		memcpy(bmd->iov, iter_iov(data), sizeof(struct iovec) * data->nr_segs);
+		bmd->iter.__iov = bmd->iov;
+	}
+	return bmd;
+}
+
+/**
+ * bio_copy_from_iter - copy all pages from iov_iter to bio
+ * @bio: The &struct bio which describes the I/O as destination
+ * @iter: iov_iter as source
+ *
+ * Copy all pages from iov_iter to bio.
+ * Returns 0 on success, or error on failure.
  */
-int blk_rq_append_bio(struct request *rq, struct bio **bio)
+static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter)
 {
-	struct bio *orig_bio = *bio;
-	struct bvec_iter iter;
-	struct bio_vec bv;
-	unsigned int nr_segs = 0;
+	struct bio_vec *bvec;
+	struct bvec_iter_all iter_all;
 
-	blk_queue_bounce(rq->q, bio);
+	bio_for_each_segment_all(bvec, bio, iter_all) {
+		ssize_t ret;
 
-	bio_for_each_bvec(bv, *bio, iter)
-		nr_segs++;
+		ret = copy_page_from_iter(bvec->bv_page,
+					  bvec->bv_offset,
+					  bvec->bv_len,
+					  iter);
 
-	if (!rq->bio) {
-		blk_rq_bio_prep(rq, *bio, nr_segs);
-	} else {
-		if (!ll_back_merge_fn(rq, *bio, nr_segs)) {
-			if (orig_bio != *bio) {
-				bio_put(*bio);
-				*bio = orig_bio;
-			}
-			return -EINVAL;
-		}
+		if (!iov_iter_count(iter))
+			break;
 
-		rq->biotail->bi_next = *bio;
-		rq->biotail = *bio;
-		rq->__data_len += (*bio)->bi_iter.bi_size;
+		if (ret < bvec->bv_len)
+			return -EFAULT;
 	}
 
 	return 0;
 }
-EXPORT_SYMBOL(blk_rq_append_bio);
 
-static int __blk_rq_unmap_user(struct bio *bio)
+/**
+ * bio_copy_to_iter - copy all pages from bio to iov_iter
+ * @bio: The &struct bio which describes the I/O as source
+ * @iter: iov_iter as destination
+ *
+ * Copy all pages from bio to iov_iter.
+ * Returns 0 on success, or error on failure.
+ */
+static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter)
+{
+	struct bio_vec *bvec;
+	struct bvec_iter_all iter_all;
+
+	bio_for_each_segment_all(bvec, bio, iter_all) {
+		ssize_t ret;
+
+		ret = copy_page_to_iter(bvec->bv_page,
+					bvec->bv_offset,
+					bvec->bv_len,
+					&iter);
+
+		if (!iov_iter_count(&iter))
+			break;
+
+		if (ret < bvec->bv_len)
+			return -EFAULT;
+	}
+
+	return 0;
+}
+
+/**
+ *	bio_uncopy_user	-	finish previously mapped bio
+ *	@bio: bio being terminated
+ *
+ *	Free pages allocated from bio_copy_user_iov() and write back data
+ *	to user space in case of a read.
+ */
+static int bio_uncopy_user(struct bio *bio)
 {
+	struct bio_map_data *bmd = bio->bi_private;
 	int ret = 0;
 
-	if (bio) {
-		if (bio_flagged(bio, BIO_USER_MAPPED))
-			bio_unmap_user(bio);
-		else
-			ret = bio_uncopy_user(bio);
+	if (!bmd->is_null_mapped) {
+		/*
+		 * if we're in a workqueue, the request is orphaned, so
+		 * don't copy into a random user address space, just free
+		 * and return -EINTR so user space doesn't expect any data.
+		 */
+		if (!current->mm)
+			ret = -EINTR;
+		else if (bio_data_dir(bio) == READ)
+			ret = bio_copy_to_iter(bio, bmd->iter);
+		if (bmd->is_our_pages)
+			bio_free_pages(bio);
+	}
+	kfree(bmd);
+	return ret;
+}
+
+static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data,
+		struct iov_iter *iter, gfp_t gfp_mask)
+{
+	struct bio_map_data *bmd;
+	struct page *page;
+	struct bio *bio;
+	int i = 0, ret;
+	int nr_pages;
+	unsigned int len = iter->count;
+	unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0;
+
+	bmd = bio_alloc_map_data(iter, gfp_mask);
+	if (!bmd)
+		return -ENOMEM;
+
+	/*
+	 * We need to do a deep copy of the iov_iter including the iovecs.
+	 * The caller provided iov might point to an on-stack or otherwise
+	 * shortlived one.
+	 */
+	bmd->is_our_pages = !map_data;
+	bmd->is_null_mapped = (map_data && map_data->null_mapped);
+
+	nr_pages = bio_max_segs(DIV_ROUND_UP(offset + len, PAGE_SIZE));
+
+	ret = -ENOMEM;
+	bio = bio_kmalloc(nr_pages, gfp_mask);
+	if (!bio)
+		goto out_bmd;
+	bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, req_op(rq));
+
+	if (map_data) {
+		nr_pages = 1U << map_data->page_order;
+		i = map_data->offset / PAGE_SIZE;
+	}
+	while (len) {
+		unsigned int bytes = PAGE_SIZE;
+
+		bytes -= offset;
+
+		if (bytes > len)
+			bytes = len;
+
+		if (map_data) {
+			if (i == map_data->nr_entries * nr_pages) {
+				ret = -ENOMEM;
+				goto cleanup;
+			}
+
+			page = map_data->pages[i / nr_pages];
+			page += (i % nr_pages);
+
+			i++;
+		} else {
+			page = alloc_page(GFP_NOIO | gfp_mask);
+			if (!page) {
+				ret = -ENOMEM;
+				goto cleanup;
+			}
+		}
+
+		if (bio_add_pc_page(rq->q, bio, page, bytes, offset) < bytes) {
+			if (!map_data)
+				__free_page(page);
+			break;
+		}
+
+		len -= bytes;
+		offset = 0;
+	}
+
+	if (map_data)
+		map_data->offset += bio->bi_iter.bi_size;
+
+	/*
+	 * success
+	 */
+	if (iov_iter_rw(iter) == WRITE &&
+	     (!map_data || !map_data->null_mapped)) {
+		ret = bio_copy_from_iter(bio, iter);
+		if (ret)
+			goto cleanup;
+	} else if (map_data && map_data->from_user) {
+		struct iov_iter iter2 = *iter;
+
+		/* This is the copy-in part of SG_DXFER_TO_FROM_DEV. */
+		iter2.data_source = ITER_SOURCE;
+		ret = bio_copy_from_iter(bio, &iter2);
+		if (ret)
+			goto cleanup;
+	} else {
+		if (bmd->is_our_pages)
+			zero_fill_bio(bio);
+		iov_iter_advance(iter, bio->bi_iter.bi_size);
 	}
 
+	bio->bi_private = bmd;
+
+	ret = blk_rq_append_bio(rq, bio);
+	if (ret)
+		goto cleanup;
+	return 0;
+cleanup:
+	if (!map_data)
+		bio_free_pages(bio);
+	bio_uninit(bio);
+	kfree(bio);
+out_bmd:
+	kfree(bmd);
 	return ret;
 }
 
-static int __blk_rq_map_user_iov(struct request *rq,
-		struct rq_map_data *map_data, struct iov_iter *iter,
-		gfp_t gfp_mask, bool copy)
+static void blk_mq_map_bio_put(struct bio *bio)
 {
-	struct request_queue *q = rq->q;
-	struct bio *bio, *orig_bio;
+	if (bio->bi_opf & REQ_ALLOC_CACHE) {
+		bio_put(bio);
+	} else {
+		bio_uninit(bio);
+		kfree(bio);
+	}
+}
+
+static struct bio *blk_rq_map_bio_alloc(struct request *rq,
+		unsigned int nr_vecs, gfp_t gfp_mask)
+{
+	struct bio *bio;
+
+	if (rq->cmd_flags & REQ_ALLOC_CACHE && (nr_vecs <= BIO_INLINE_VECS)) {
+		bio = bio_alloc_bioset(NULL, nr_vecs, rq->cmd_flags, gfp_mask,
+					&fs_bio_set);
+		if (!bio)
+			return NULL;
+	} else {
+		bio = bio_kmalloc(nr_vecs, gfp_mask);
+		if (!bio)
+			return NULL;
+		bio_init(bio, NULL, bio->bi_inline_vecs, nr_vecs, req_op(rq));
+	}
+	return bio;
+}
+
+static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
+		gfp_t gfp_mask)
+{
+	iov_iter_extraction_t extraction_flags = 0;
+	unsigned int max_sectors = queue_max_hw_sectors(rq->q);
+	unsigned int nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS);
+	struct bio *bio;
 	int ret;
+	int j;
 
-	if (copy)
-		bio = bio_copy_user_iov(q, map_data, iter, gfp_mask);
-	else
-		bio = bio_map_user_iov(q, iter, gfp_mask);
+	if (!iov_iter_count(iter))
+		return -EINVAL;
 
-	if (IS_ERR(bio))
-		return PTR_ERR(bio);
+	bio = blk_rq_map_bio_alloc(rq, nr_vecs, gfp_mask);
+	if (bio == NULL)
+		return -ENOMEM;
+
+	if (blk_queue_pci_p2pdma(rq->q))
+		extraction_flags |= ITER_ALLOW_P2PDMA;
+	if (iov_iter_extract_will_pin(iter))
+		bio_set_flag(bio, BIO_PAGE_PINNED);
+
+	while (iov_iter_count(iter)) {
+		struct page *stack_pages[UIO_FASTIOV];
+		struct page **pages = stack_pages;
+		ssize_t bytes;
+		size_t offs;
+		int npages;
+
+		if (nr_vecs > ARRAY_SIZE(stack_pages))
+			pages = NULL;
+
+		bytes = iov_iter_extract_pages(iter, &pages, LONG_MAX,
+					       nr_vecs, extraction_flags, &offs);
+		if (unlikely(bytes <= 0)) {
+			ret = bytes ? bytes : -EFAULT;
+			goto out_unmap;
+		}
 
-	bio->bi_opf &= ~REQ_OP_MASK;
-	bio->bi_opf |= req_op(rq);
+		npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
+
+		if (unlikely(offs & queue_dma_alignment(rq->q)))
+			j = 0;
+		else {
+			for (j = 0; j < npages; j++) {
+				struct page *page = pages[j];
+				unsigned int n = PAGE_SIZE - offs;
+				bool same_page = false;
+
+				if (n > bytes)
+					n = bytes;
+
+				if (!bio_add_hw_page(rq->q, bio, page, n, offs,
+						     max_sectors, &same_page))
+					break;
+
+				if (same_page)
+					bio_release_page(bio, page);
+				bytes -= n;
+				offs = 0;
+			}
+		}
+		/*
+		 * release the pages we didn't map into the bio, if any
+		 */
+		while (j < npages)
+			bio_release_page(bio, pages[j++]);
+		if (pages != stack_pages)
+			kvfree(pages);
+		/* couldn't stuff something into bio? */
+		if (bytes) {
+			iov_iter_revert(iter, bytes);
+			break;
+		}
+	}
+
+	ret = blk_rq_append_bio(rq, bio);
+	if (ret)
+		goto out_unmap;
+	return 0;
+
+ out_unmap:
+	bio_release_pages(bio, false);
+	blk_mq_map_bio_put(bio);
+	return ret;
+}
+
+static void bio_invalidate_vmalloc_pages(struct bio *bio)
+{
+#ifdef ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE
+	if (bio->bi_private && !op_is_write(bio_op(bio))) {
+		unsigned long i, len = 0;
+
+		for (i = 0; i < bio->bi_vcnt; i++)
+			len += bio->bi_io_vec[i].bv_len;
+		invalidate_kernel_vmap_range(bio->bi_private, len);
+	}
+#endif
+}
+
+static void bio_map_kern_endio(struct bio *bio)
+{
+	bio_invalidate_vmalloc_pages(bio);
+	bio_uninit(bio);
+	kfree(bio);
+}
+
+/**
+ *	bio_map_kern	-	map kernel address into bio
+ *	@q: the struct request_queue for the bio
+ *	@data: pointer to buffer to map
+ *	@len: length in bytes
+ *	@gfp_mask: allocation flags for bio allocation
+ *
+ *	Map the kernel address into a bio suitable for io to a block
+ *	device. Returns an error pointer in case of error.
+ */
+static struct bio *bio_map_kern(struct request_queue *q, void *data,
+		unsigned int len, gfp_t gfp_mask)
+{
+	unsigned long kaddr = (unsigned long)data;
+	unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	unsigned long start = kaddr >> PAGE_SHIFT;
+	const int nr_pages = end - start;
+	bool is_vmalloc = is_vmalloc_addr(data);
+	struct page *page;
+	int offset, i;
+	struct bio *bio;
+
+	bio = bio_kmalloc(nr_pages, gfp_mask);
+	if (!bio)
+		return ERR_PTR(-ENOMEM);
+	bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, 0);
+
+	if (is_vmalloc) {
+		flush_kernel_vmap_range(data, len);
+		bio->bi_private = data;
+	}
+
+	offset = offset_in_page(kaddr);
+	for (i = 0; i < nr_pages; i++) {
+		unsigned int bytes = PAGE_SIZE - offset;
+
+		if (len <= 0)
+			break;
+
+		if (bytes > len)
+			bytes = len;
+
+		if (!is_vmalloc)
+			page = virt_to_page(data);
+		else
+			page = vmalloc_to_page(data);
+		if (bio_add_pc_page(q, bio, page, bytes,
+				    offset) < bytes) {
+			/* we don't support partial mappings */
+			bio_uninit(bio);
+			kfree(bio);
+			return ERR_PTR(-EINVAL);
+		}
+
+		data += bytes;
+		len -= bytes;
+		offset = 0;
+	}
+
+	bio->bi_end_io = bio_map_kern_endio;
+	return bio;
+}
+
+static void bio_copy_kern_endio(struct bio *bio)
+{
+	bio_free_pages(bio);
+	bio_uninit(bio);
+	kfree(bio);
+}
+
+static void bio_copy_kern_endio_read(struct bio *bio)
+{
+	char *p = bio->bi_private;
+	struct bio_vec *bvec;
+	struct bvec_iter_all iter_all;
 
-	orig_bio = bio;
+	bio_for_each_segment_all(bvec, bio, iter_all) {
+		memcpy_from_bvec(p, bvec);
+		p += bvec->bv_len;
+	}
+
+	bio_copy_kern_endio(bio);
+}
+
+/**
+ *	bio_copy_kern	-	copy kernel address into bio
+ *	@q: the struct request_queue for the bio
+ *	@data: pointer to buffer to copy
+ *	@len: length in bytes
+ *	@gfp_mask: allocation flags for bio and page allocation
+ *	@reading: data direction is READ
+ *
+ *	copy the kernel address into a bio suitable for io to a block
+ *	device. Returns an error pointer in case of error.
+ */
+static struct bio *bio_copy_kern(struct request_queue *q, void *data,
+		unsigned int len, gfp_t gfp_mask, int reading)
+{
+	unsigned long kaddr = (unsigned long)data;
+	unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	unsigned long start = kaddr >> PAGE_SHIFT;
+	struct bio *bio;
+	void *p = data;
+	int nr_pages = 0;
 
 	/*
-	 * We link the bounce buffer in and could have to traverse it
-	 * later so we have to get a ref to prevent it from being freed
+	 * Overflow, abort
 	 */
-	ret = blk_rq_append_bio(rq, &bio);
-	if (ret) {
-		__blk_rq_unmap_user(orig_bio);
-		return ret;
+	if (end < start)
+		return ERR_PTR(-EINVAL);
+
+	nr_pages = end - start;
+	bio = bio_kmalloc(nr_pages, gfp_mask);
+	if (!bio)
+		return ERR_PTR(-ENOMEM);
+	bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, 0);
+
+	while (len) {
+		struct page *page;
+		unsigned int bytes = PAGE_SIZE;
+
+		if (bytes > len)
+			bytes = len;
+
+		page = alloc_page(GFP_NOIO | __GFP_ZERO | gfp_mask);
+		if (!page)
+			goto cleanup;
+
+		if (!reading)
+			memcpy(page_address(page), p, bytes);
+
+		if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
+			break;
+
+		len -= bytes;
+		p += bytes;
+	}
+
+	if (reading) {
+		bio->bi_end_io = bio_copy_kern_endio_read;
+		bio->bi_private = data;
+	} else {
+		bio->bi_end_io = bio_copy_kern_endio;
+	}
+
+	return bio;
+
+cleanup:
+	bio_free_pages(bio);
+	bio_uninit(bio);
+	kfree(bio);
+	return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * Append a bio to a passthrough request.  Only works if the bio can be merged
+ * into the request based on the driver constraints.
+ */
+int blk_rq_append_bio(struct request *rq, struct bio *bio)
+{
+	struct bvec_iter iter;
+	struct bio_vec bv;
+	unsigned int nr_segs = 0;
+
+	bio_for_each_bvec(bv, bio, iter)
+		nr_segs++;
+
+	if (!rq->bio) {
+		blk_rq_bio_prep(rq, bio, nr_segs);
+	} else {
+		if (!ll_back_merge_fn(rq, bio, nr_segs))
+			return -EINVAL;
+		rq->biotail->bi_next = bio;
+		rq->biotail = bio;
+		rq->__data_len += (bio)->bi_iter.bi_size;
+		bio_crypt_free_ctx(bio);
 	}
-	bio_get(bio);
 
 	return 0;
 }
+EXPORT_SYMBOL(blk_rq_append_bio);
+
+/* Prepare bio for passthrough IO given ITER_BVEC iter */
+static int blk_rq_map_user_bvec(struct request *rq, const struct iov_iter *iter)
+{
+	struct request_queue *q = rq->q;
+	size_t nr_iter = iov_iter_count(iter);
+	size_t nr_segs = iter->nr_segs;
+	struct bio_vec *bvecs, *bvprvp = NULL;
+	const struct queue_limits *lim = &q->limits;
+	unsigned int nsegs = 0, bytes = 0;
+	struct bio *bio;
+	size_t i;
+
+	if (!nr_iter || (nr_iter >> SECTOR_SHIFT) > queue_max_hw_sectors(q))
+		return -EINVAL;
+	if (nr_segs > queue_max_segments(q))
+		return -EINVAL;
+
+	/* no iovecs to alloc, as we already have a BVEC iterator */
+	bio = blk_rq_map_bio_alloc(rq, 0, GFP_KERNEL);
+	if (bio == NULL)
+		return -ENOMEM;
+
+	bio_iov_bvec_set(bio, (struct iov_iter *)iter);
+	blk_rq_bio_prep(rq, bio, nr_segs);
+
+	/* loop to perform a bunch of sanity checks */
+	bvecs = (struct bio_vec *)iter->bvec;
+	for (i = 0; i < nr_segs; i++) {
+		struct bio_vec *bv = &bvecs[i];
+
+		/*
+		 * If the queue doesn't support SG gaps and adding this
+		 * offset would create a gap, fallback to copy.
+		 */
+		if (bvprvp && bvec_gap_to_prev(lim, bvprvp, bv->bv_offset)) {
+			blk_mq_map_bio_put(bio);
+			return -EREMOTEIO;
+		}
+		/* check full condition */
+		if (nsegs >= nr_segs || bytes > UINT_MAX - bv->bv_len)
+			goto put_bio;
+		if (bytes + bv->bv_len > nr_iter)
+			goto put_bio;
+		if (bv->bv_offset + bv->bv_len > PAGE_SIZE)
+			goto put_bio;
+
+		nsegs++;
+		bytes += bv->bv_len;
+		bvprvp = bv;
+	}
+	return 0;
+put_bio:
+	blk_mq_map_bio_put(bio);
+	return -EINVAL;
+}
 
 /**
  * blk_rq_map_user_iov - map user data to a request, for passthrough requests
@@ -110,44 +628,52 @@ static int __blk_rq_map_user_iov(struct request *rq,
  *
  *    A matching blk_rq_unmap_user() must be issued at the end of I/O, while
  *    still in process context.
- *
- *    Note: The mapped bio may need to be bounced through blk_queue_bounce()
- *    before being submitted to the device, as pages mapped may be out of
- *    reach. It's the callers responsibility to make sure this happens. The
- *    original bio must be passed back in to blk_rq_unmap_user() for proper
- *    unmapping.
  */
 int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
 			struct rq_map_data *map_data,
 			const struct iov_iter *iter, gfp_t gfp_mask)
 {
-	bool copy = false;
+	bool copy = false, map_bvec = false;
 	unsigned long align = q->dma_pad_mask | queue_dma_alignment(q);
 	struct bio *bio = NULL;
 	struct iov_iter i;
 	int ret = -EINVAL;
 
-	if (!iter_is_iovec(iter))
-		goto fail;
-
 	if (map_data)
 		copy = true;
+	else if (blk_queue_may_bounce(q))
+		copy = true;
 	else if (iov_iter_alignment(iter) & align)
 		copy = true;
+	else if (iov_iter_is_bvec(iter))
+		map_bvec = true;
+	else if (!user_backed_iter(iter))
+		copy = true;
 	else if (queue_virt_boundary(q))
 		copy = queue_virt_boundary(q) & iov_iter_gap_alignment(iter);
 
+	if (map_bvec) {
+		ret = blk_rq_map_user_bvec(rq, iter);
+		if (!ret)
+			return 0;
+		if (ret != -EREMOTEIO)
+			goto fail;
+		/* fall back to copying the data on limits mismatches */
+		copy = true;
+	}
+
 	i = *iter;
 	do {
-		ret =__blk_rq_map_user_iov(rq, map_data, &i, gfp_mask, copy);
+		if (copy)
+			ret = bio_copy_user_iov(rq, map_data, &i, gfp_mask);
+		else
+			ret = bio_map_user_iov(rq, &i, gfp_mask);
 		if (ret)
 			goto unmap_rq;
 		if (!bio)
 			bio = rq->bio;
 	} while (iov_iter_count(&i));
 
-	if (!bio_flagged(bio, BIO_USER_MAPPED))
-		rq->rq_flags |= RQF_COPY_USER;
 	return 0;
 
 unmap_rq:
@@ -162,9 +688,8 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
 		    struct rq_map_data *map_data, void __user *ubuf,
 		    unsigned long len, gfp_t gfp_mask)
 {
-	struct iovec iov;
 	struct iov_iter i;
-	int ret = import_single_range(rq_data_dir(rq), ubuf, len, &iov, &i);
+	int ret = import_ubuf(rq_data_dir(rq), ubuf, len, &i);
 
 	if (unlikely(ret < 0))
 		return ret;
@@ -173,6 +698,42 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
 }
 EXPORT_SYMBOL(blk_rq_map_user);
 
+int blk_rq_map_user_io(struct request *req, struct rq_map_data *map_data,
+		void __user *ubuf, unsigned long buf_len, gfp_t gfp_mask,
+		bool vec, int iov_count, bool check_iter_count, int rw)
+{
+	int ret = 0;
+
+	if (vec) {
+		struct iovec fast_iov[UIO_FASTIOV];
+		struct iovec *iov = fast_iov;
+		struct iov_iter iter;
+
+		ret = import_iovec(rw, ubuf, iov_count ? iov_count : buf_len,
+				UIO_FASTIOV, &iov, &iter);
+		if (ret < 0)
+			return ret;
+
+		if (iov_count) {
+			/* SG_IO howto says that the shorter of the two wins */
+			iov_iter_truncate(&iter, buf_len);
+			if (check_iter_count && !iov_iter_count(&iter)) {
+				kfree(iov);
+				return -EINVAL;
+			}
+		}
+
+		ret = blk_rq_map_user_iov(req->q, req, map_data, &iter,
+				gfp_mask);
+		kfree(iov);
+	} else if (buf_len) {
+		ret = blk_rq_map_user(req->q, req, map_data, ubuf, buf_len,
+				gfp_mask);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(blk_rq_map_user_io);
+
 /**
  * blk_rq_unmap_user - unmap a request with user data
  * @bio:	       start of bio list
@@ -184,21 +745,21 @@ EXPORT_SYMBOL(blk_rq_map_user);
  */
 int blk_rq_unmap_user(struct bio *bio)
 {
-	struct bio *mapped_bio;
+	struct bio *next_bio;
 	int ret = 0, ret2;
 
 	while (bio) {
-		mapped_bio = bio;
-		if (unlikely(bio_flagged(bio, BIO_BOUNCED)))
-			mapped_bio = bio->bi_private;
-
-		ret2 = __blk_rq_unmap_user(mapped_bio);
-		if (ret2 && !ret)
-			ret = ret2;
+		if (bio->bi_private) {
+			ret2 = bio_uncopy_user(bio);
+			if (ret2 && !ret)
+				ret = ret2;
+		} else {
+			bio_release_pages(bio, bio_data_dir(bio) == READ);
+		}
 
-		mapped_bio = bio;
+		next_bio = bio;
 		bio = bio->bi_next;
-		bio_put(mapped_bio);
+		blk_mq_map_bio_put(next_bio);
 	}
 
 	return ret;
@@ -223,8 +784,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 {
 	int reading = rq_data_dir(rq) == READ;
 	unsigned long addr = (unsigned long) kbuf;
-	int do_copy = 0;
-	struct bio *bio, *orig_bio;
+	struct bio *bio;
 	int ret;
 
 	if (len > (queue_max_hw_sectors(q) << 9))
@@ -232,8 +792,8 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 	if (!len || !kbuf)
 		return -EINVAL;
 
-	do_copy = !blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf);
-	if (do_copy)
+	if (!blk_rq_aligned(q, addr, len) || object_is_on_stack(kbuf) ||
+	    blk_queue_may_bounce(q))
 		bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
 	else
 		bio = bio_map_kern(q, kbuf, len, gfp_mask);
@@ -244,17 +804,11 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 	bio->bi_opf &= ~REQ_OP_MASK;
 	bio->bi_opf |= req_op(rq);
 
-	if (do_copy)
-		rq->rq_flags |= RQF_COPY_USER;
-
-	orig_bio = bio;
-	ret = blk_rq_append_bio(rq, &bio);
+	ret = blk_rq_append_bio(rq, bio);
 	if (unlikely(ret)) {
-		/* request is too big */
-		bio_put(orig_bio);
-		return ret;
+		bio_uninit(bio);
+		kfree(bio);
 	}
-
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL(blk_rq_map_kern);