drbd: Starting with protocol 96 we can allow app-IO while receiving the bitmap
* C_STARTING_SYNC_S, C_STARTING_SYNC_T In these states the bitmap gets written to disk. Locking out of app-IO is done by using the drbd_queue_bitmap_io() and drbd_bitmap_io() functions these days. It is no longer necessary to lock out app-IO based on the connection state. App-IO that may come in after the BITMAP_IO flag got cleared before the state transition to C_SYNC_(SOURCE|TARGET) does not get mirrored, sets a bit in the local bitmap, that is already set, therefore changes nothing. * C_WF_BITMAP_S In this state we send updates (P_OUT_OF_SYNC packets). With that we make sure they have the same number of bits when going into the C_SYNC_(SOURCE|TARGET) connection state. * C_UNCONNECTED: The receiver starts, no need to lock out IO. * C_DISCONNECTING: in drbd_disconnect() we had a wait_event() to wait until ap_bio_cnt reaches 0. Removed that. * C_TIMEOUT, C_BROKEN_PIPE, C_NETWORK_FAILURE C_PROTOCOL_ERROR, C_TEAR_DOWN: Same as C_DISCONNECTING * C_WF_REPORT_PARAMS: IO still possible since that is still like C_WF_CONNECTION. And we do not need to send barriers in C_WF_BITMAP_S connection state. Allow concurrent accesses to the bitmap when receiving the bitmap. Everything gets ORed anyways. A drbd_free_tl_hash() is in after_state_chg_work(). At that point all the work items of the last connections must have been processed. Introduced a call to drbd_free_tl_hash() into drbd_free_mdev() for paranoia reasons. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Showing
Please register or sign in to comment