bio: safeguard REQ_ALLOC_CACHE bio put

isilence · axboe · commit d4347d50407d · 2022-10-20T05:50:29.000-07:00
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>
diff --git 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);

Original file line number	Diff line number	Diff line change
`@@ -741,7 +741,7 @@ void bio_put(struct bio *bio)`
`741`	`741`	`return;`
`742`	`742`	`}`
`743`	`743`
`744`		`- if (bio->bi_opf & REQ_ALLOC_CACHE) {`
	`744`	`+ if ((bio->bi_opf & REQ_ALLOC_CACHE) && !WARN_ON_ONCE(in_interrupt())) {`
`745`	`745`	`struct bio_alloc_cache *cache;`
`746`	`746`
`747`	`747`	`bio_uninit(bio);`