diff options
| -rw-r--r-- | block/blk-map.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/block/blk-map.c b/block/blk-map.c index c07d9c8317f..ab43533ba64 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -5,6 +5,7 @@ #include <linux/module.h> #include <linux/bio.h> #include <linux/blkdev.h> +#include <scsi/sg.h> /* for struct sg_iovec */ #include "blk.h" @@ -194,15 +195,26 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, struct sg_iovec *iov, int iov_count, unsigned int len) { struct bio *bio; + int i, read = rq_data_dir(rq) == READ; + int unaligned = 0; if (!iov || iov_count <= 0) return -EINVAL; - /* we don't allow misaligned data like bio_map_user() does. If the - * user is using sg, they're expected to know the alignment constraints - * and respect them accordingly */ - bio = bio_map_user_iov(q, NULL, iov, iov_count, - rq_data_dir(rq) == READ); + for (i = 0; i < iov_count; i++) { + unsigned long uaddr = (unsigned long)iov[i].iov_base; + + if (uaddr & queue_dma_alignment(q)) { + unaligned = 1; + break; + } + } + + if (unaligned || (q->dma_pad_mask & len)) + bio = bio_copy_user_iov(q, iov, iov_count, read); + else + bio = bio_map_user_iov(q, NULL, iov, iov_count, read); + if (IS_ERR(bio)) return PTR_ERR(bio); |