diff options
Diffstat (limited to 'block/blk-map.c')
| -rw-r--r-- | block/blk-map.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/block/blk-map.c b/block/blk-map.c index 572140cda5f..4849fa36161 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -42,7 +42,7 @@ static int __blk_rq_unmap_user(struct bio *bio) static int __blk_rq_map_user(struct request_queue *q, struct request *rq, struct rq_map_data *map_data, void __user *ubuf, - unsigned int len, gfp_t gfp_mask) + unsigned int len, int null_mapped, gfp_t gfp_mask) { unsigned long uaddr; struct bio *bio, *orig_bio; @@ -63,6 +63,9 @@ static int __blk_rq_map_user(struct request_queue *q, struct request *rq, if (IS_ERR(bio)) return PTR_ERR(bio); + if (null_mapped) + bio->bi_flags |= (1 << BIO_NULL_MAPPED); + orig_bio = bio; blk_queue_bounce(q, &bio); @@ -111,12 +114,17 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq, { unsigned long bytes_read = 0; struct bio *bio = NULL; - int ret; + int ret, null_mapped = 0; if (len > (q->max_hw_sectors << 9)) return -EINVAL; - if (!len || !ubuf) + if (!len) return -EINVAL; + if (!ubuf) { + if (!map_data || rq_data_dir(rq) != READ) + return -EINVAL; + null_mapped = 1; + } while (bytes_read != len) { unsigned long map_len, end, start; @@ -135,7 +143,7 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq, map_len -= PAGE_SIZE; ret = __blk_rq_map_user(q, rq, map_data, ubuf, map_len, - gfp_mask); + null_mapped, gfp_mask); if (ret < 0) goto unmap_rq; if (!bio) |