On 03/01/2018 12:39 PM, Zhai Zhaoxuan wrote:
> The function cached_dev_make_request() and flash_dev_make_request() call
> generic_start_io_acct() with (struct bcache_device)->disk when they start a
> closure. Then the function bio_complete() calls generic_end_io_acct() with
> (struct search)->orig_bio->bi_disk when the closure has done.
> Since the `bi_disk` is not the bcache device, the generic_end_io_acct() is
> called with a wrong device queue.
>
> It causes the "inflight" (in struct hd_struct) counter keep increasing
> without decreasing.
>
> This patch fix the problem by calling generic_end_io_acct() with
> (struct bcache_device)->disk.
>
> Signed-off-by: Zhai Zhaoxuan <kxuanobj@xxxxxxxxx>
Hi Zhaoxuan,
Nice catch, it makes sense. Thanks.
Reviewed-by: Coly Li <colyli@xxxxxxx>
One more question, do you experience any problem when inflight counter
increases only ? I just wondering.
Coly
> ---
> drivers/md/bcache/request.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
> index 643c3021624f..83de85fe4542 100644
> --- a/drivers/md/bcache/request.c
> +++ b/drivers/md/bcache/request.c
> @@ -611,8 +611,8 @@ static void request_endio(struct bio *bio)
> static void bio_complete(struct search *s)
> {
> if (s->orig_bio) {
> - struct request_queue *q = s->orig_bio->bi_disk->queue;
> - generic_end_io_acct(q, bio_data_dir(s->orig_bio),
> + generic_end_io_acct(s->d->disk->queue,
> + bio_data_dir(s->orig_bio),
> &s->d->disk->part0, s->start_time);
>
> trace_bcache_request_end(s->d, s->orig_bio);
>
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