4.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Al Viro <v...@zeniv.linux.org.uk>
commit 1cfd0ddd82232804e03f3023f6a58b50dfef0574 upstream.
Since "block: support large requests in blk_rq_map_user_iov" we
started to call it with partially drained iter; that works fine
on the write side, but reads create a copy of iter for completion
time. And that needs to take the possibility of ->iov_iter != 0
into account...
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
block/bio.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/block/bio.c
+++ b/block/bio.c
@@ -1235,8 +1235,8 @@ struct bio *bio_copy_user_iov(struct req
*/
bmd->is_our_pages = map_data ? 0 : 1;
memcpy(bmd->iov, iter->iov, sizeof(struct iovec) * iter->nr_segs);
- iov_iter_init(&bmd->iter, iter->type, bmd->iov,
- iter->nr_segs, iter->count);
+ bmd->iter = *iter;
+ bmd->iter.iov = bmd->iov;
ret = -ENOMEM;
bio = bio_kmalloc(gfp_mask, nr_pages);
