Merge "blk-mq: Avoid that submitting a bio concurrently with device removal triggers a crash" (793c2ecb) · Commits · e / devices / android_kernel_xiaomi_nabu

block/blk-core.c

+29 −4

Original line number	Diff line number	Diff line
		@@ -2222,8 +2222,20 @@ blk_qc_t generic_make_request(struct bio *bio)
		* yet.
		*/
		struct bio_list bio_list_on_stack[2];
		bool flags = 0;
		struct request_queue *q = bio->bi_disk->queue;
		blk_qc_t ret = BLK_QC_T_NONE;

		if (bio->bi_opf & REQ_NOWAIT)
		flags = BLK_MQ_REQ_NOWAIT;
		if (blk_queue_enter(q, flags) < 0) {
		if (!blk_queue_dying(q) && (bio->bi_opf & REQ_NOWAIT))
		bio_wouldblock_error(bio);
		else
		bio_io_error(bio);
		return ret;
		}

		if (!generic_make_request_checks(bio))
		goto out;

		@@ -2260,9 +2272,22 @@ blk_qc_t generic_make_request(struct bio *bio)
		bio_list_init(&bio_list_on_stack[0]);
		current->bio_list = bio_list_on_stack;
		do {
		struct request_queue *q = bio->bi_disk->queue;
		bool enter_succeeded = true;

		if (likely(blk_queue_enter(q, bio->bi_opf & REQ_NOWAIT) == 0)) {
		if (unlikely(q != bio->bi_disk->queue)) {
		if (q)
		blk_queue_exit(q);
		q = bio->bi_disk->queue;
		flags = 0;
		if (bio->bi_opf & REQ_NOWAIT)
		flags = BLK_MQ_REQ_NOWAIT;
		if (blk_queue_enter(q, flags) < 0) {
		enter_succeeded = false;
		q = NULL;
		}
		}

		if (enter_succeeded) {
		struct bio_list lower, same;

		/* Create a fresh bio_list for all subordinate requests */
		@@ -2270,8 +2295,6 @@ blk_qc_t generic_make_request(struct bio *bio)
		bio_list_init(&bio_list_on_stack[0]);
		ret = q->make_request_fn(q, bio);

		blk_queue_exit(q);

		/* sort new bios into those for a lower level
		* and those for the same level
		*/
		@@ -2298,6 +2321,8 @@ blk_qc_t generic_make_request(struct bio *bio)
		current->bio_list = NULL; /* deactivate */

		out:
		if (q)
		blk_queue_exit(q);
		return ret;
		}
		EXPORT_SYMBOL(generic_make_request);