From 14eacf12dbc75352fa746dfd9e24de3170ba5ff5 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Thu, 11 Apr 2019 08:23:29 +0200
Subject: [PATCH] block: don't allow multiple bio_iov_iter_get_pages calls per
bio
No caller uses bio_iov_iter_get_pages multiple times on a given bio,
and that funtionality isn't all that useful. Removing it will make
some future changes a little easier and also simplifies the function
a bit.
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
block/bio.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index ad346082a9719..c2a389b1509a6 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -958,7 +958,10 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
{
const bool is_bvec = iov_iter_is_bvec(iter);
- unsigned short orig_vcnt = bio->bi_vcnt;
+ int ret;
+
+ if (WARN_ON_ONCE(bio->bi_vcnt))
+ return -EINVAL;
/*
* If this is a BVEC iter, then the pages are kernel pages. Don't
@@ -968,19 +971,13 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
bio_set_flag(bio, BIO_NO_PAGE_REF);
do {
- int ret;
-
if (is_bvec)
ret = __bio_iov_bvec_add_pages(bio, iter);
else
ret = __bio_iov_iter_get_pages(bio, iter);
+ } while (!ret && iov_iter_count(iter) && !bio_full(bio));
- if (unlikely(ret))
- return bio->bi_vcnt > orig_vcnt ? 0 : ret;
-
- } while (iov_iter_count(iter) && !bio_full(bio));
-
- return 0;
+ return bio->bi_vcnt ? 0 : ret;
}
static void submit_bio_wait_endio(struct bio *bio)
--
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