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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Pavel Begunkov <asml.silence@gmail.com>,
        Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
        Sasha Levin <sashal@kernel.org>, linux-block@vger.kernel.org
Subject: [PATCH AUTOSEL 6.0 34/34] bio: safeguard REQ_ALLOC_CACHE bio put
Date:   Tue,  1 Nov 2022 07:27:26 -0400
Message-Id: <20221101112726.799368-34-sashal@kernel.org>
In-Reply-To: <20221101112726.799368-1-sashal@kernel.org>
References: <20221101112726.799368-1-sashal@kernel.org>
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From: Pavel Begunkov <asml.silence@gmail.com>

[ Upstream commit d4347d50407daea6237872281ece64c4bdf1ec99 ]

bio_put() with REQ_ALLOC_CACHE assumes that it's executed not from
an irq context. Let's add a warning if the invariant is not respected,
especially since there is a couple of places removing REQ_POLLED by hand
without also clearing REQ_ALLOC_CACHE.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/558d78313476c4e9c233902efa0092644c3d420a.1666122465.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 block/bio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/bio.c b/block/bio.c
index 77e3b764a078..fc2364cf1775 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -741,7 +741,7 @@ void bio_put(struct bio *bio)
 			return;
 	}
 
-	if (bio->bi_opf & REQ_ALLOC_CACHE) {
+	if ((bio->bi_opf & REQ_ALLOC_CACHE) && !WARN_ON_ONCE(in_interrupt())) {
 		struct bio_alloc_cache *cache;
 
 		bio_uninit(bio);
-- 
2.35.1