在 2023/7/1 7:53, Song Liu 写道:

On Tue, Jun 27, 2023 at 6:58 PM [off-list ref] wrote:

quoted

[...]

quoted

+static void get_rdev_repl_from_mirror(struct raid10_info *mirror,
+                                struct md_rdev **prdev,
+                                struct md_rdev **prrdev)
+{
+       struct md_rdev *rdev, *rrdev;
+
+       rrdev = rcu_dereference(mirror->replacement);
+       /*
+        * Read replacement first to prevent reading both rdev and
+        * replacement as NULL during replacement replace rdev.
+        */
+       smp_mb();
+       rdev = rcu_dereference(mirror->rdev);
+       if (rdev == rrdev)
+               rrdev = NULL;
+
+       *prrdev = rrdev;
+       *prdev = rdev;

I don't think the reduction in duplicated code justifies two output arguments.

How about

static struct md_rdev *dereference_rdev_and_rrdev(struct raid10_info *mirror,
                                struct md_rdev **prrdev)
{
     ...
     *prrdev = xxx;
     return rdev;
}

So we only have one argument for output.

Also, "from_mirror" in the function name doesn't really add more value.

Thanks,
Song
.

I agree. Let me improve this.

-- 
Thanks,
Nan