Commit ad3fc798 authored by Guoqing Jiang's avatar Guoqing Jiang Committed by Song Liu
Browse files

md: revert io stats accounting 

The commit 41d2d848 ("md: improve io stats accounting") could cause
double fault problem per the report [1], and also it is not correct to
change ->bi_end_io if md don't own it, so let's revert it.

And io stats accounting will be replemented in later commits.

[1]. https://lore.kernel.org/linux-raid/3bf04253-3fad-434a-63a7-20214e38cf26@gmail.com/T/#t



Fixes: 41d2d848 ("md: improve io stats accounting")
Signed-off-by: default avatarGuoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: default avatarSong Liu <song@kernel.org>
parent d07f3b08

drivers/md/md.c

+0 −45
Original line number Diff line number Diff line
@@ -441,30 +441,6 @@ void md_handle_request(struct mddev *mddev, struct bio *bio) 
}

EXPORT_SYMBOL(md_handle_request);



struct md_io {

	struct mddev *mddev;

	bio_end_io_t *orig_bi_end_io;

	void *orig_bi_private;

	struct block_device *orig_bi_bdev;

	unsigned long start_time;

};



static void md_end_io(struct bio *bio)

{

	struct md_io *md_io = bio->bi_private;

	struct mddev *mddev = md_io->mddev;



	bio_end_io_acct_remapped(bio, md_io->start_time, md_io->orig_bi_bdev);



	bio->bi_end_io = md_io->orig_bi_end_io;

	bio->bi_private = md_io->orig_bi_private;



	mempool_free(md_io, &mddev->md_io_pool);



	if (bio->bi_end_io)

		bio->bi_end_io(bio);

}



static blk_qc_t md_submit_bio(struct bio *bio)

{

	const int rw = bio_data_dir(bio);
@@ -489,21 +465,6 @@ static blk_qc_t md_submit_bio(struct bio *bio) 
		return BLK_QC_T_NONE;

	}



	if (bio->bi_end_io != md_end_io) {

		struct md_io *md_io;



		md_io = mempool_alloc(&mddev->md_io_pool, GFP_NOIO);

		md_io->mddev = mddev;

		md_io->orig_bi_end_io = bio->bi_end_io;

		md_io->orig_bi_private = bio->bi_private;

		md_io->orig_bi_bdev = bio->bi_bdev;



		bio->bi_end_io = md_end_io;

		bio->bi_private = md_io;



		md_io->start_time = bio_start_io_acct(bio);

	}



	/* bio could be mergeable after passing to underlayer */

	bio->bi_opf &= ~REQ_NOMERGE;
@@ -5608,7 +5569,6 @@ static void md_free(struct kobject *ko) 


	bioset_exit(&mddev->bio_set);

	bioset_exit(&mddev->sync_set);

	mempool_exit(&mddev->md_io_pool);

	kfree(mddev);

}
@@ -5705,11 +5665,6 @@ static int md_alloc(dev_t dev, char *name) 
		 */

		mddev->hold_active = UNTIL_STOP;



	error = mempool_init_kmalloc_pool(&mddev->md_io_pool, BIO_POOL_SIZE,

					  sizeof(struct md_io));

	if (error)

		goto abort;



	error = -ENOMEM;

	mddev->queue = blk_alloc_queue(NUMA_NO_NODE);

	if (!mddev->queue)

drivers/md/md.h

+0 −1
Original line number Diff line number Diff line
@@ -487,7 +487,6 @@ struct mddev { 
	struct bio_set			sync_set; /* for sync operations like

						   * metadata and bitmap writes

						   */

	mempool_t			md_io_pool;



	/* Generic flush handling.

	 * The last to finish preflush schedules a worker to submit