| Message ID | 1712979908-6132-1-git-send-email-mmgu@volanscomputer.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | block: fix bio_copy_user_iov() for SG_DXFER_TO_FROM_DEV case | expand |
diff --git a/block/blk-map.c b/block/blk-map.c index 71210cd..eca02d9 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -211,11 +211,12 @@ static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data, if (ret) goto cleanup; } else if (map_data && map_data->from_user) { - struct iov_iter iter2 = *iter; + bool tmp = iter->data_source; /* This is the copy-in part of SG_DXFER_TO_FROM_DEV. */ - iter2.data_source = ITER_SOURCE; - ret = bio_copy_from_iter(bio, &iter2); + iter->data_source = ITER_SOURCE; + ret = bio_copy_from_iter(bio, iter); + iter->data_source = tmp; if (ret) goto cleanup; } else {
Commit "block: Fix WARNING in _copy_from_iter" is insufficient to make SG_IO ioctl with a transfer direction of SG_DXFER_TO_FROM_DEV work; the passed in iterator should be advanced after bio_copy_from_iter(). Otherwise its caller, blk_rq_map_user_iov(), will return -EINVAL due to a wrong loop condition. Instead of using a copy of the passed iterator, save iter->data_source and restore it after bio_copy_from_iter(). Signed-off-by: Mingming Gu <mmgu@volanscomputer.com> --- block/blk-map.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)