From: Ming Lei <ming.lei@redhat.com>
Date: Wed, 24 Apr 2019 11:01:46 +0000 (+0800)
Subject: block: don't run get_page() on pages from non-bvec iov iter
X-Git-Tag: v5.2-rc1~22^2~73
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0257c0ed5ea3de3e32cb322852c4c40bc09d1b97;p=thirdparty%2Fkernel%2Flinux.git

block: don't run get_page() on pages from non-bvec iov iter

The refcount has been increased for pages retrieved from non-bvec iov iter
via __bio_iov_iter_get_pages(), so don't need to do that again.

Otherwise, IO pages are leaked easily.

Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Fixes: 7321ecbfc7cf ("block: change how we get page references in bio_iov_iter_get_pages")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/block/bio.c b/block/bio.c
index c81ed2dfee530..662d45752ec53 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -992,7 +992,7 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
 
 	if (iov_iter_bvec_no_ref(iter))
 		bio_set_flag(bio, BIO_NO_PAGE_REF);
-	else
+	else if (is_bvec)
 		bio_get_pages(bio);
 
 	return bio->bi_vcnt ? 0 : ret;