Following the recommendation from Christoph.... This moves the eh_timed_out functionality from the scsi_host_template to the transport_template. Given that this is now a transport function, the EH_RESET_TIMER case no longer caps the timer reschedulings. The transport guarantees that this is not an infinite condition. This patch is dependent upon Christoph's change of: http://marc.theaimsgroup.com/?l=linux-scsi&m=113923531412919&w=2 -- james s Original Post: http://marc.theaimsgroup.com/?l=linux-scsi&m=113924339701796&w=2 diff -upNr a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c --- a/drivers/scsi/scsi_error.c 2006-02-06 12:00:11.000000000 -0500 +++ b/drivers/scsi/scsi_error.c 2006-02-07 09:13:49.000000000 -0500 @@ -29,6 +29,7 @@ #include <scsi/scsi_dbg.h> #include <scsi/scsi_device.h> #include <scsi/scsi_eh.h> +#include <scsi/scsi_transport.h> #include <scsi/scsi_host.h> #include <scsi/scsi_ioctl.h> #include <scsi/scsi_request.h> @@ -163,16 +164,12 @@ void scsi_times_out(struct scsi_cmnd *sc { scsi_log_completion(scmd, TIMEOUT_ERROR); - if (scmd->device->host->hostt->eh_timed_out) - switch (scmd->device->host->hostt->eh_timed_out(scmd)) { + if (scmd->device->host->transportt->eh_timed_out) + switch (scmd->device->host->transportt->eh_timed_out(scmd)) { case EH_HANDLED: __scsi_done(scmd); return; case EH_RESET_TIMER: - /* This allows a single retry even of a command - * with allowed == 0 */ - if (scmd->retries++ > scmd->allowed) - break; scsi_add_timer(scmd, scmd->timeout_per_command, scsi_times_out); return; diff -upNr a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c --- a/drivers/scsi/scsi_transport_fc.c 2006-02-06 12:00:11.000000000 -0500 +++ b/drivers/scsi/scsi_transport_fc.c 2006-02-07 09:01:04.000000000 -0500 @@ -31,6 +31,7 @@ #include <scsi/scsi_host.h> #include <scsi/scsi_transport.h> #include <scsi/scsi_transport_fc.h> +#include <scsi/scsi_cmnd.h> #include "scsi_priv.h" /* @@ -1090,6 +1091,40 @@ static int fc_rport_match(struct attribu } +/** + * fc_timed_out - FC Transport I/O timeout intercept handler + * + * @scmd: The SCSI command which timed out + * + * This routine protects against error handlers getting invoked while a + * rport is in a blocked state, typically due to a temporarily loss of + * connectivity. If the error handlers are allowed to proceed, requests + * to abort i/o, reset the target, etc will likely fail as there is no way + * to communicate with the device to perform the requested function. These + * failures may result in the midlayer taking the device offline, requiring + * manual intervention to restore operation. + * + * This routine, called whenever an i/o times out, validates the state of + * the underlying rport. If the rport is blocked, it returns + * EH_RESET_TIMER, which will continue to reschedule the timeout. + * Eventually, either the device will return, or devloss_tmo will fire, + * and when the timeout then fires, it will be handled normally. + * If the rport is not blocked, normal error handling continues. + * + * Notes: + * This routine assumes no locks are held on entry. + **/ +static enum scsi_eh_timer_return +fc_timed_out(struct scsi_cmnd *scmd) +{ + struct fc_rport *rport = starget_to_rport(scsi_target(scmd->device)); + + if (rport->port_state == FC_PORTSTATE_BLOCKED) + return EH_RESET_TIMER; + + return EH_NOT_HANDLED; +} + /* * Must be called with shost->host_lock held */ @@ -1146,6 +1181,8 @@ fc_attach_transport(struct fc_function_t /* Transport uses the shost workq for scsi scanning */ i->t.create_work_queue = 1; + i->t.eh_timed_out = fc_timed_out; + i->t.user_scan = fc_user_scan; /* diff -upNr a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h --- a/include/scsi/scsi_host.h 2006-02-06 12:00:33.000000000 -0500 +++ b/include/scsi/scsi_host.h 2006-02-06 13:15:22.000000000 -0500 @@ -147,20 +147,6 @@ struct scsi_host_template { int (* eh_host_reset_handler)(struct scsi_cmnd *); /* - * This is an optional routine to notify the host that the scsi - * timer just fired. The returns tell the timer routine what to - * do about this: - * - * EH_HANDLED: I fixed the error, please complete the command - * EH_RESET_TIMER: I need more time, reset the timer and - * begin counting again - * EH_NOT_HANDLED Begin normal error recovery - * - * Status: OPTIONAL - */ - enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *); - - /* * Before the mid layer attempts to scan for a new device where none * currently exists, it will call this entry in your driver. Should * your driver need to allocate any structs or perform any other init diff -upNr a/include/scsi/scsi_transport.h b/include/scsi/scsi_transport.h --- a/include/scsi/scsi_transport.h 2006-02-06 12:00:33.000000000 -0500 +++ b/include/scsi/scsi_transport.h 2006-02-06 13:14:57.000000000 -0500 @@ -48,6 +48,17 @@ struct scsi_transport_template { * True if the transport wants to use a host-based work-queue */ unsigned int create_work_queue : 1; + + /* + * This is an optional routine that allows the transport to become + * involved when a scsi io timer fires. The return value tells the + * timer routine how to finish the io timeout handling: + * EH_HANDLED: I fixed the error, please complete the command + * EH_RESET_TIMER: I need more time, reset the timer and + * begin counting again + * EH_NOT_HANDLED Begin normal error recovery + */ + enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *); }; #define transport_class_to_shost(tc) \ - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
