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md: revert io stats accounting

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commit ad3fc798800fb7ca04c1dfc439dba946818048d8 upstream.

The commit 41d2d848e5c0 ("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: 41d2d848e5c0 ("md: improve io stats accounting")
Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
[GM: backport to 5.10-stable]
Signed-off-by: Guillaume Morin <guillaume@morinfr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Guoqing Jiang 2021-05-25 17:46:16 +08:00 committed by Greg Kroah-Hartman
parent df395c763b
commit c39d68ab38
2 changed files with 12 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
drivers/md/md.c
View File

@ -459,34 +459,12 @@ check_suspended:
}
EXPORT_SYMBOL(md_handle_request);
struct md_io {
struct mddev *mddev;
bio_end_io_t *orig_bi_end_io;
void *orig_bi_private;
unsigned long start_time;
struct hd_struct *part;
};
static void md_end_io(struct bio *bio)
{
struct md_io *md_io = bio->bi_private;
struct mddev *mddev = md_io->mddev;
part_end_io_acct(md_io->part, bio, md_io->start_time);
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);
const int sgrp = op_stat_group(bio_op(bio));
struct mddev *mddev = bio->bi_disk->private_data;
unsigned int sectors;
if (mddev == NULL || mddev->pers == NULL) {
bio_io_error(bio);
@ -507,26 +485,21 @@ 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;
bio->bi_end_io = md_end_io;
bio->bi_private = md_io;
md_io->start_time = part_start_io_acct(mddev->gendisk,
&md_io->part, bio);
}
/*
* save the sectors now since our bio can
* go away inside make_request
*/
sectors = bio_sectors(bio);
/* bio could be mergeable after passing to underlayer */
bio->bi_opf &= ~REQ_NOMERGE;
md_handle_request(mddev, bio);
part_stat_lock();
part_stat_inc(&mddev->gendisk->part0, ios[sgrp]);
part_stat_add(&mddev->gendisk->part0, sectors[sgrp], sectors);
part_stat_unlock();
return BLK_QC_T_NONE;
}
@ -5636,7 +5609,6 @@ 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);
}
@ -5732,11 +5704,6 @@ 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)

1
drivers/md/md.h
View File

@ -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