Hi, this is the final patch-series to make dlm reliable when re-connection occurs. You can easily generate a couple of re-connections by running:
tcpkill -9 -i $IFACE port 21064 on your own to test these patches. At some time dlm will detect message drops and will re-transmit messages if necessary. It introduces a new dlm protocol behaviour and increases the dlm protocol version. I tested it with SCTP as well and tried to be backwards compatible with dlm protocol version 3.1. However I don't recommend at all to mix these versions in a setup since dlm version 3.2 fixes long-term issues. - Alex changes since v3: - add comment about why queues are unbound - move rcu usage to version receive handler changes since v2: - make timer handling pending only if messages are on air, the sync isn't quite correct there but doesn't need to be precise - use before() from tcp to check if seq is before other seq with respect of overflows - change srcu handling to hold srcu in all places where nodes are referencing - we should not get a disadvantage of holding that lock. We should update also lowcomms regarding to that. - add some WARN_ON() to check that nothing in send/recv is going anymore otherwise it's likely an issue. - add more future work regarding to fencing of nodes if over cluster manager timeout/bad seq happens - add note about missing length size check of tail payload (resource name length) regarding to the receive buffer - remove some include which isn't necessary in recoverd.c Thanks to Paolo Abeni for his review and recommendations. Alexander Aring (8): fs: dlm: public header in out utility fs: dlm: add more midcomms hooks fs: dlm: make buffer handling per msg fs: dlm: add functionality to re-transmit a message fs: dlm: move out some hash functionality fs: dlm: add union in dlm header for lockspace id fs: dlm: add reliable connection if reconnect fs: dlm: don't allow half transmitted messages fs/dlm/config.c | 3 +- fs/dlm/dlm_internal.h | 35 +- fs/dlm/lock.c | 14 +- fs/dlm/lockspace.c | 14 +- fs/dlm/lowcomms.c | 197 +++++-- fs/dlm/lowcomms.h | 23 +- fs/dlm/member.c | 12 +- fs/dlm/midcomms.c | 1307 ++++++++++++++++++++++++++++++++++++++++- fs/dlm/midcomms.h | 10 + fs/dlm/rcom.c | 63 +- fs/dlm/util.c | 10 +- fs/dlm/util.h | 2 + 12 files changed, 1577 insertions(+), 113 deletions(-) -- 2.26.3
