Commit 00387bd2 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

bcache: use bvec_kmap_local in bch_data_verify 



Using local kmaps slightly reduces the chances to stray writes, and
the bvec interface cleans up the code a little bit.

Also switch from page_address to bvec_kmap_local for cbv to be on the
safe side and to avoid pointlessly poking into bvec internals.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarColy Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20211020143812.6403-8-colyli@suse.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 0f5cd781

drivers/md/bcache/debug.c

+5 −6
Original line number Diff line number Diff line
@@ -127,21 +127,20 @@ void bch_data_verify(struct cached_dev *dc, struct bio *bio) 


	citer.bi_size = UINT_MAX;

	bio_for_each_segment(bv, bio, iter) {

		void *p1 = kmap_atomic(bv.bv_page);

		void *p1 = bvec_kmap_local(&bv);

		void *p2;



		cbv = bio_iter_iovec(check, citer);

		p2 = page_address(cbv.bv_page);

		p2 = bvec_kmap_local(&cbv);



		cache_set_err_on(memcmp(p1 + bv.bv_offset,

					p2 + bv.bv_offset,

					bv.bv_len),

		cache_set_err_on(memcmp(p1, p2, bv.bv_len),

				 dc->disk.c,

				 "verify failed at dev %pg sector %llu",

				 dc->bdev,

				 (uint64_t) bio->bi_iter.bi_sector);



		kunmap_atomic(p1);

		kunmap_local(p2);

		kunmap_local(p1);

		bio_advance_iter(check, &citer, bv.bv_len);

	}