在 2023/8/9 20:11, Michal Koutný 写道:
On Wed, Aug 09, 2023 at 07:29:28PM +0800, Li Lingfeng <lilingfeng@xxxxxxxxxxxxxxx> wrote:
1 file changed, 10 insertions(+), 24 deletions(-)
I like this bottom line.
@@ -861,7 +838,16 @@ static ssize_t iolatency_set_limit(struct kernfs_open_file *of, char *buf,
blkg_conf_init(&ctx, buf);
- ret = blk_iolatency_try_init(&ctx);
+ ret = blkg_conf_open_bdev(&ctx);
+ if (ret)
+ goto out;
+
+ /*
+ * blk_iolatency_init() may fail after rq_qos_add() succeeds which can
+ * confuse iolat_rq_qos() test. Make the test and init atomic.
+ */
Perhaps add here
lockdep_assert_held(ctx.bdev->bd_queue->rq_qos_mutex);
because without that the last sentence of the comment misses the
context.
Yes, it looks better.
Thanks.
Li
+ if (!iolat_rq_qos(ctx.bdev->bd_queue))
+ ret = blk_iolatency_init(ctx.bdev->bd_disk);
if (ret)
goto out;
Thanks,
Michal
