From: NeilBrown Date: Thu, 8 Dec 2011 04:49:12 +0000 (+1100) Subject: md: refine interpretation of "hold_active == UNTIL_IOCTL". X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1d23f178d56ae1349b4fc5108ac8f4f8cdc92afc;p=linux-beck.git md: refine interpretation of "hold_active == UNTIL_IOCTL". We like md devices to disappear when they really are not needed. However it is not possible to tell from the current state whether it is needed or not. We can only tell from recent history of changes. In particular immediately after we create an md device it looks very similar to immediately after we have finished with it. So we always preserve a newly created md device until something significant happens. This state is stored in 'hold_active'. The normal case is to keep it until an ioctl happens, as that will normally either activate it, or explicitly de-activate it. If it doesn't then it was probably created by mistake and it is now time to get rid of it. We can also modify an array via sysfs (instead of via ioctl) and we currently treat any change via sysfs like an ioctl as a sign that if it now isn't more active, it should be destroyed. However this is not appropriate as changes made via sysfs are more gradual so we should look for a more definitive change. So this patch only clears 'hold_active' from UNTIL_IOCTL to clear when the array_state is changed via sysfs. Other changes via sysfs are ignored. Signed-off-by: NeilBrown --- diff --git a/drivers/md/md.c b/drivers/md/md.c index 84acfe7d10e4..93b0da133507 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -3788,6 +3788,8 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len) if (err) return err; else { + if (mddev->hold_active == UNTIL_IOCTL) + mddev->hold_active = 0; sysfs_notify_dirent_safe(mddev->sysfs_state); return len; } @@ -4508,8 +4510,6 @@ md_attr_store(struct kobject *kobj, struct attribute *attr, if (!capable(CAP_SYS_ADMIN)) return -EACCES; rv = mddev_lock(mddev); - if (mddev->hold_active == UNTIL_IOCTL) - mddev->hold_active = 0; if (!rv) { rv = entry->store(mddev, page, length); mddev_unlock(mddev);