Commit e8c75ee9 authored by Li Ruilin's avatar Li Ruilin Committed by Zheng Zengkai
Browse files

bcache: Rewrite patch to delay to invalidate cache data 

euleros inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4LOJ6


CVE: NA

------------------------------

The recently pushd bugfix patch "Delay to invalidate cache data
in writearound write" has a stupid copy&paste bug, which causes
bypassed write request will never invalidate data in cache device,
causing a data corruption. This patch fixes this corruption.
This patch also ensures that the writeback lock is released after
data insert.

Fixes: 6a1d9c41b367 ("bcache: Delay to invalidate cache data in writearound write")
Signed-off-by: default avatarLi Ruilin <liruilin4@huawei.com>
Signed-off-by: default avatarSong Chao <chao.song@huawei.com>
Reviewed-by: default avatarPeng Junyi <pengjunyi1@huawei.com>
Acked-by: default avatarXie Xiuqi <xiexiuqi@huawei.com>
Signed-off-by: default avatarCheng Jian <cj.chengjian@huawei.com>
Reviewed-by: default avatarGuangxing Deng <dengguangxing@huawei.com>
Reviewed-by: default avatarchao song <chao.song@huawei.com>
Reviewed-by: default avatarchao song <chao.song@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 87f258f0

drivers/md/bcache/request.c

+11 −4
Original line number Diff line number Diff line
@@ -735,6 +735,8 @@ struct search *search_alloc(struct bio *bio, 
	/* Count on the bcache device */

	s->start_time		= part_start_io_acct(d->disk, &s->part, bio);

	s->prefetch		= prefetch;

	s->write_inval_data_putoff = false;



	s->iop.c		= d->c;

	s->iop.bio		= NULL;

	s->iop.inode		= d->id;
@@ -755,6 +757,10 @@ static void cached_dev_bio_complete(struct closure *cl) 
	struct search *s = container_of(cl, struct search, cl);

	struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);



	/* eusure this lock is released after data_insert */

	if (s->write_inval_data_putoff)

		up_read_non_owner(&dc->writeback_lock);



	cached_dev_put(dc);

	search_free(cl);

}
@@ -993,9 +999,9 @@ static void cached_dev_write_complete(struct closure *cl) 
	struct search *s = container_of(cl, struct search, cl);

	struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);



	if (!s->iop.bypass)

	if (s->write_inval_data_putoff)

		closure_call(&s->iop.cl, bch_data_insert, NULL, cl);



	else

		up_read_non_owner(&dc->writeback_lock);

	continue_at(cl, cached_dev_bio_complete, NULL);

}
@@ -1048,6 +1054,7 @@ static void cached_dev_write(struct cached_dev *dc, struct search *s) 
		bio->bi_end_io = backing_request_endio;

		closure_bio_submit(s->iop.c, bio, cl);



		s->write_inval_data_putoff = true;

	} else if (s->iop.writeback) {

		bch_writeback_add(dc);

		s->iop.bio = bio;
@@ -1080,7 +1087,7 @@ static void cached_dev_write(struct cached_dev *dc, struct search *s) 
	}



insert_data:

	if (!s->iop.bypass)

	if (!s->write_inval_data_putoff)

		closure_call(&s->iop.cl, bch_data_insert, NULL, cl);

	continue_at(cl, cached_dev_write_complete, NULL);

}

drivers/md/bcache/request.h

+13 −0
Original line number Diff line number Diff line
@@ -65,6 +65,19 @@ struct search { 
	unsigned long		start_time;

	/* for prefetch, we do not need copy data to bio */

	bool			prefetch;

	/*

	 * The function bch_data_insert() is invoked asynchronously as the bio

	 * subbmited to backend block device, therefore there may be a read

	 * request subbmited after the bch_data_insert() done and ended before

	 * the backend bio is end. This read request will read data from the

	 * backend block device, and insert dirty data to cache device. However

	 * by writearound cache mode, bcache will not invalidate data again,

	 * so that read request after will read dirty data from the cache,

	 * causing a data corruption.

	 * So that we should put off this invalidation. This switch is for this

	 * put off.

	 */

	bool			write_inval_data_putoff;

	struct list_head	list_node;

	wait_queue_head_t	wqh;

	struct acache_info	smp;