On 7/9/25 08:44, 余快 wrote:
Hi,
在 2025/7/8 19:57, Hannes Reinecke 写道:
On 7/8/25 13:31, 余快 wrote:
Hi,
Hannes Reinecke <hare@xxxxxxx <mailto:hare@xxxxxxx>> 于2025年7月8日周二
14:29写道：
> + if (mddev->bitmap_ops->group && !mddev_is_dm(mddev)) {
> + if (sysfs_create_group(&mddev->kobj, mddev-
>bitmap_ops->group))
> + pr_warn("md: cannot register extra bitmap
attributes for %s\n",
> + mdname(mddev));
> + else
> + kobject_uevent(&mddev->kobj, KOBJ_CHANGE);
> + }
> return true;
>
> err:
Ouch. This will cause havoc with the udev rules.
Having different events for 'add' and 'change' tends to confuse udev
rules (most treat 'add' and 'change' identically), so at the very
least
you would need to document this.
Do you mean document here as new sysfs entries are created under mddev
kobject?
No, I meant to document that 'add' events will have access to
different sysfs attributes than the 'change' events.
In the running system one will only see the final status, so it's not
immediately obvious that some attributes are only valid for 'change',
and not for 'add'.
Thanks for the explanation, just to make sure you mean:
diff --git a/Documentation/admin-guide/md.rst
b/Documentation/admin-guide/md.rst
index 2030772075b5..db7a39894c8d 100644
--- a/Documentation/admin-guide/md.rst
+++ b/Documentation/admin-guide/md.rst
@@ -388,6 +388,9 @@ All md devices contain:
bitmap
The default internal bitmap
+If bitmap_type is not none, then additional bitmap attributes will be
created
+after md device KOBJ_CHANGE event.
+
If bitmap_type is bitmap, then the md device will also contain:
bitmap/location
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 22378686a964..60e2de23c9b5 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -699,6 +699,7 @@ static bool mddev_set_bitmap_ops(struct mddev *mddev)
pr_warn("md: cannot register extra bitmap
attributes for %s\n",
mdname(mddev));
else
+ /* Inform user with KOBJ_CHANGE about new bitmap
attributes. */
kobject_uevent(&mddev->kobj, KOBJ_CHANGE);
}
return true;
Yes, that's what I had in mind.
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich
