dm: simplify flush_bio initialization in __send_empty_flush (47d95102) · Commits · 戴 / test

We don't really need the struct block_device to initialize a bio. So switch from using bio_set_dev to manually setting up bi_disk (bi_partno will always be zero and has been cleared by bio_init already). Signed-off-by:

Christoph Hellwig <hch@lst.de> Reviewed-by:

Hannes Reinecke <hare@suse.de> Acked-by:

Mike Snitzer <snitzer@redhat.com> Signed-off-by:

Jens Axboe <axboe@kernel.dk>

drivers/md/dm.c

+3 −9

Original line number	Diff line number	Diff line
		@@ -1422,18 +1422,12 @@ static int __send_empty_flush(struct clone_info *ci)
		*/
		bio_init(&flush_bio, NULL, 0);
		flush_bio.bi_opf = REQ_OP_WRITE \| REQ_PREFLUSH \| REQ_SYNC;
		flush_bio.bi_disk = ci->io->md->disk;
		bio_associate_blkg(&flush_bio);

		ci->bio = &flush_bio;
		ci->sector_count = 0;

		/*
		* Empty flush uses a statically initialized bio, as the base for
		* cloning. However, blkg association requires that a bdev is
		* associated with a gendisk, which doesn't happen until the bdev is
		* opened. So, blkg association is done at issue time of the flush
		* rather than when the device is created in alloc_dev().
		*/
		bio_set_dev(ci->bio, ci->io->md->bdev);

		BUG_ON(bio_has_data(ci->bio));
		while ((ti = dm_table_get_target(ci->map, target_nr++)))
		__send_duplicate_bios(ci, ti, ti->num_flush_bios, NULL);

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