[PATCH] block: support larger block pc requests

This patch modifies blk_rq_map/unmap_user() and the cdrom and scsi_ioctl.c
users so that it supports requests larger than bio by chaining them together.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 2 insertions, 16 deletions

diff --git a/fs/bio.c b/fs/bio.c
index d91cfbf..aa4d09b 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -560,10 +560,8 @@ struct bio *bio_copy_user(request_queue_t *q, unsigned long uaddr,
 			break;
 		}
 
-		if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) {
-			ret = -EINVAL;
+		if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
 			break;
-		}
 
 		len -= bytes;
 	}
@@ -750,7 +748,6 @@ struct bio *bio_map_user_iov(request_queue_t *q, struct block_device *bdev,
 			     int write_to_vm)
 {
 	struct bio *bio;
-	int len = 0, i;
 
 	bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm);
 
@@ -765,18 +762,7 @@ struct bio *bio_map_user_iov(request_queue_t *q, struct block_device *bdev,
 	 */
 	bio_get(bio);
 
-	for (i = 0; i < iov_count; i++)
-		len += iov[i].iov_len;
-
-	if (bio->bi_size == len)
-		return bio;
-
-	/*
-	 * don't support partial mappings
-	 */
-	bio_endio(bio, bio->bi_size, 0);
-	bio_unmap_user(bio);
-	return ERR_PTR(-EINVAL);
+	return bio;
 }
 
 static void __bio_unmap_user(struct bio *bio)