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b8853dbd8c
If the asender thread, or request_timer_fn(), or some other part of the code, decided to drop the connection (because of timeout or other), but the receiver just now was processing a P_STATE packet, there was a chance that receive_state() would do a hard state change "re-establishing" an already failed connection without additional handshake. Log excerpt: Remote failed to finish a request within ko-count * timeout peer( Secondary -> Unknown ) conn( Connected -> Timeout ) pdsk( UpToDate -> DUnknown ) asender terminated ... peer( Unknown -> Secondary ) conn( Timeout -> Connected ) pdsk( DUnknown -> UpToDate ) peer_isp( 0 -> 1 ) ... Connection closed peer( Secondary -> Unknown ) conn( Connected -> Unconnected ) pdsk( UpToDate -> DUnknown ) peer_isp( 1 -> 0 ) receiver terminated Impact: while the connection state is erroneously "Connected", requests may be queued and even sent, which would never be acknowledged, and may have been missed by the cleanup. These requests would never be completed. The next drbd_suspend_io() will then lock up, waiting forever for these requests to complete. Fixed in several code paths: Make sure the connection state is NetworkFailure or worse before starting the cleanup in drbd_disconnect(). This should make sure the cleanup won't miss any requests. Disallow receive_state() to "upgrade" the connection state from an error state. This will make sure the "illegal" state transition won't happen. For all connection failure states, relax the safe-guard in sanitize_state() again to silently mask out those state changes (e.g. Timeout -> Connected becomes Timeout -> Timeout). Note by Philipp Reisner: The 3rd chunk described as "relax the safe-guard..." is not there in 8.4 as it is relaxed to the maximum in 8.4 already Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> |
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| .. | ||
| drbd_actlog.c | ||
| drbd_bitmap.c | ||
| drbd_int.h | ||
| drbd_interval.c | ||
| drbd_interval.h | ||
| drbd_main.c | ||
| drbd_nl.c | ||
| drbd_nla.c | ||
| drbd_nla.h | ||
| drbd_proc.c | ||
| drbd_receiver.c | ||
| drbd_req.c | ||
| drbd_req.h | ||
| drbd_state.c | ||
| drbd_state.h | ||
| drbd_strings.c | ||
| drbd_vli.h | ||
| drbd_worker.c | ||
| drbd_wrappers.h | ||
| Kconfig | ||
| Makefile | ||