Re: [PATCH] driver core: fix shutdown races with probe/remove(v2)
From: Alan Stern <stern@rowland.harvard.edu>
Date: 2012-06-11 14:16:19
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On Mon, 11 Jun 2012, Ming Lei wrote:
quoted hunk ↗ jump to hunk
@@ -1820,6 +1833,18 @@ void device_shutdown(void) list_del_init(&dev->kobj.entry); spin_unlock(&devices_kset->list_lock); + /* hold lock to avoid race with .probe/.release */ + if (dev->parent && !__try_lock(dev->parent)) + nonlocked = 2; + else if (!__try_lock(dev)) + nonlocked = 1; + else + nonlocked = 0; + + if (nonlocked) + dev_err(dev, "can't hold %slock for shutdown\n", + nonlocked == 1 ? "" : "parent ");
Even if the parent can't be locked, you should still try to lock the device. Alan Stern