Mike Christie wrote:
jeykholt@xxxxxxxxx wrote:
fnic: add fnic_scsi.c and fnic_io.h.
fnic_scsi.c contains the FCP SCSI handling as well as firmware reset
and FLOGI registration handling.
I just looked at this one function, because I was fixing the same code
in fcoe.ko/libfc:fc_fcp.c
+int fnic_reset(struct Scsi_Host *shost)
+{
+ struct fc_lport *lp;
+ struct fnic *fnic;
+ unsigned long flags;
+ int ret = SUCCESS;
+ enum fnic_state old_state;
+ DECLARE_COMPLETION_ONSTACK(reset_wait);
+
+ lp = shost_priv(shost);
+ fnic = lp->drv_priv;
+
+ printk(KERN_DEBUG DFX "fnic_reset called\n", fnic->fnic_no);
+
+ /* Issue firmware reset */
+ spin_lock_irqsave(&fnic->fnic_lock, flags);
+ fnic->reset_wait = &reset_wait;
+ old_state = fnic->state;
+ fnic->state = FNIC_IN_FC_TRANS_ETH_MODE;
+ vnic_dev_del_addr(fnic->vdev, fnic->data_src_addr);
+ spin_unlock_irqrestore(&fnic->fnic_lock, flags);
+
+ if (fnic_fw_reset_handler(fnic)) {
+ spin_lock_irqsave(&fnic->fnic_lock, flags);
+ ret = FAILED;
+ if (fnic->state == FNIC_IN_FC_TRANS_ETH_MODE)
+ fnic->state = old_state;
+ fnic->reset_wait = NULL;
+ spin_unlock_irqrestore(&fnic->fnic_lock, flags);
+ goto fnic_reset_end;
+ }
+
+ /* fw reset is issued, now wait for it to complete */
+ wait_for_completion_timeout(&reset_wait,
+ msecs_to_jiffies(FNIC_HOST_RESET_TIMEOUT));
+
+ /* Check for status */
+ spin_lock_irqsave(&fnic->fnic_lock, flags);
+ fnic->reset_wait = NULL;
+ ret = (fnic->state == FNIC_IN_ETH_MODE) ? SUCCESS : FAILED;
+ spin_unlock_irqrestore(&fnic->fnic_lock, flags);
+
+ /* Now reset local port, this will clean up libFC exchanges,
+ * reset remote port sessions, and if link is up, begin flogi
+ */
+ fc_lport_lock(lp);
+ if (lp->tt.lport_reset(lp))
+ ret = FAILED;
The problem here is that this only starts the login. When fnic_reset
returns for the scsi eh path, scsi-ml is going to send a TUR to make
sure that we are ready to go. If we are not the devices will be
offlined. So unless it is a really quick relogin we are going to offline
the devices by accident.
Well - what should be happening is - prior to the reset or as part of
it, the fc transport fc_remote_port_delete() call should be made on all
those remote ports that connectivity is about to be terminated on. This
will place all the associated targets/luns on those rports into a
blocked state, and start the devloss timer on them. This will suspend
the eh path as well. Thus, things suspend until either the driver/fcoe
stack re-login's and re-calls the transport with the same remote port
(thus the transport will unblock the targets/luns), or devloss_tmo
expires, at which time it is correct to report loss of connectivity.
Of course, all this assumes the fc_host stays in existence.
For fc_fcp.c I added a hokey loop and wait like some other drivers. We
could instead have libfc notify any waiters of a state change here. We
could also do a rport blocked timedout helper, convert the fc drivers
and use it here so we only wait for the login to complete or for the
port block to fail.
-- james s
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