On 8/19/2015 13:02, Al Viro wrote: > On Wed, Aug 19, 2015 at 02:56:50PM +1000, NeilBrown wrote: >> If not, we need to clean up and try again. >> To do this we need to check MNT_SYNC_UMOUNT. >> If that is clear it is safe and best to call mntput() on the mnt. >> If it is set, then we just do the mnt_add_count(mnt, -1) and give up >> completely. > > It's more subtle, actually. See my reply upthread for details, but > basically we rely on rcu_read_lock() held since before that MNT_SYNC_UMOUNT > had been set, making synchronize_rcu() in namespace_unlock() a guaranteed > delay of the final mntput until after we have returned. > Thanks for the comments. I will update this patch according to Neil's comments and __legitimize_mnt. thanks, Kinglong Mee -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
