diff options
Diffstat (limited to 'block/ll_rw_blk.c')
| -rw-r--r-- | block/ll_rw_blk.c | 28 |
1 files changed, 16 insertions, 12 deletions
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index a66ec30855d..e07c079e07e 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -2405,6 +2405,7 @@ int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf, unsigned long len) { unsigned long bytes_read = 0; + struct bio *bio = NULL; int ret; if (len > (q->max_hw_sectors << 9)) @@ -2431,6 +2432,8 @@ int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf, ret = __blk_rq_map_user(q, rq, ubuf, map_len); if (ret < 0) goto unmap_rq; + if (!bio) + bio = rq->bio; bytes_read += ret; ubuf += ret; } @@ -2438,7 +2441,7 @@ int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf, rq->buffer = rq->data = NULL; return 0; unmap_rq: - blk_rq_unmap_user(rq); + blk_rq_unmap_user(bio); return ret; } @@ -2495,29 +2498,30 @@ EXPORT_SYMBOL(blk_rq_map_user_iov); /** * blk_rq_unmap_user - unmap a request with user data - * @rq: rq to be unmapped + * @bio: start of bio list * * Description: - * Unmap a rq previously mapped by blk_rq_map_user(). - * rq->bio must be set to the original head of the request. + * Unmap a rq previously mapped by blk_rq_map_user(). The caller must + * supply the original rq->bio from the blk_rq_map_user() return, since + * the io completion may have changed rq->bio. */ -int blk_rq_unmap_user(struct request *rq) +int blk_rq_unmap_user(struct bio *bio) { - struct bio *bio, *mapped_bio; + struct bio *mapped_bio; int ret = 0, ret2; - while ((bio = rq->bio)) { - if (bio_flagged(bio, BIO_BOUNCED)) + while (bio) { + mapped_bio = bio; + if (unlikely(bio_flagged(bio, BIO_BOUNCED))) mapped_bio = bio->bi_private; - else - mapped_bio = bio; ret2 = __blk_rq_unmap_user(mapped_bio); if (ret2 && !ret) ret = ret2; - rq->bio = bio->bi_next; - bio_put(bio); + mapped_bio = bio; + bio = bio->bi_next; + bio_put(mapped_bio); } return ret; |