[SCSI] libfc: Track rogue remote ports
Rogue ports are currently not tracked on any list. The only reference to them is through any outstanding exchanges pending on the rogue ports. If the module is removed while a retry is set on a rogue port (say a Plogi retry for instance), this retry is not cancelled because there is no reference to the rogue port in the discovery rports list. Thus the local port can clean itself up, delete the exchange pool, and then the rogue port timeout can fire and try to start up another exchange. This patch tracks the rogue ports in a new list disc->rogue_rports. Creating a new list instead of using the disc->rports list keeps remote port code change to a minimum. 1) Whenever a rogue port is created, it is immediately added to the disc->rogue_rports list. 2) When the rogues port goes to ready, it is removed from the rogue list and the real remote port is added to the disc->rports list 3) The removal of the rogue from the disc->rogue_rports list is done in the context of the fc_rport_work() workQ thread in discovery callback. 4) Real rports are removed from the disc->rports list like before. Lookup is done only in the real rports list. This avoids making large changes to the remote port code. 5) In fc_disc_stop_rports, the rogues list is traversed in addition to the real list to stop the rogue ports and issue logoffs on them. This way, rogue ports get cleaned up when the local port goes away. 6) rogue remote ports are not removed from the list right away, but removed late in fc_rport_work() context, multiple threads can find the same remote port in the list and call rport_logoff(). Rport_logoff() only continues with the logoff if port is not in NONE state, thus preventing multiple logoffs and multiple list deletions. 7) Since the rport is removed from the disc list at a later stage (in the disc callback), incoming frames can find the rport even if rport_logoff() has been called on the rport. When rport_logoff() is called, the rport state is set to NONE, and we are trying to cancel all exchanges and retries on that port. While in this state, if an incoming Plogi/Prli/Logo or other frames match the rport, we should not reply because the rport is in the NONE state. Just drop the frame, since the rport will be deleted soon in the disc callback (fc_rport_work) 8) In fc_disc_single(), remove rport lookup and call to fc_disc_del_target. fc_disc_single() is called from recv_rscn_req() where rport lookup and rport_logoff is already done. Signed-off-by: NAbhijeet Joglekar <abjoglek@cisco.com> Signed-off-by: NRobert Love <robert.w.love@intel.com> Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
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