On Tue, May 03, 2016 at 10:22:13PM -0400, Guoqing Jiang wrote: > Some code waits for a metadata update by: > > 1. flagging that it is needed (MD_CHANGE_DEVS or MD_CHANGE_CLEAN) > 2. setting MD_CHANGE_PENDING and waking the management thread > 3. waiting for MD_CHANGE_PENDING to be cleared > > If the first two are done without locking, the code in md_update_sb() > which checks if it needs to repeat might test if an update is needed > before step 1, then clear MD_CHANGE_PENDING after step 2, resulting > in the wait returning early. > > So make sure all places that set MD_CHANGE_PENDING are atomicial, and > bit_clear_unless (suggested by Neil) is introduced for the purpose. Applied the 3, thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
