On Thu, Apr 23, 2015 at 12:16:21PM +0000, Holger Hoffstätte wrote: > After staring at this (and the Lovecraftian horrors of free_extent_buffer()) > for over an hour and trying to understand how and why this could even remotely > work, I cannot help but think that this fix would shift the race to the much > smaller window between the test_bit and the first spin_lock. Btw, I had exactly the same concerns, as this is close to the classical example of a shared resource check outside of the critical section. But the extent buffers are protected by more than just the spinlock and if the race mentioned above happens, the lifted reference counts will prevent to drop the last one. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
