scsi: zfcp: Move shost modification after QDIO (re-)open into fenced function

When establishing and activating the QDIO queue pair for a FCP device for
the first time, or after an adapter recovery, we publish some of its
characteristics to the scsi host object representing that FCP device.

When moving the scsi host object allocation and registration to after the
first exchange config and exchange port data, this is not possible for the
former case - QDIO open for the first time - because that happens before
exchange config and exchange port data.

Move the scsi host object update into a fenced function that checks whether
the object already exists or not. This way we can repeat that step later,
once we are past the allocation.

Once the first recovery succeeds we don't release the scsi host object
anymore, so further recoveries do work as before.

Link: https://lore.kernel.org/r/a214ebf508f71e3690113e3e90edab1cea0e24e3.1588956679.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index 88294ca0e2ea0bd7474e174d329203dc6ad9ee89..d67f31b9b8599658185565fd59b1520e044f280d 100644 (file)
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -153,6 +153,8 @@ extern int zfcp_qdio_sbal_get(struct zfcp_qdio *);
 extern int zfcp_qdio_send(struct zfcp_qdio *, struct zfcp_qdio_req *);
 extern int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *, struct zfcp_qdio_req *,
                                   struct scatterlist *);
+extern void zfcp_qdio_shost_update(struct zfcp_adapter *const adapter,
+                                  const struct zfcp_qdio *const qdio);
 extern int zfcp_qdio_open(struct zfcp_qdio *);
 extern void zfcp_qdio_close(struct zfcp_qdio *);
 extern void zfcp_qdio_siosl(struct zfcp_adapter *);

diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c
index 26702b56a7ab88d5a6d5d5eba70f02620025160f..3a7f3374d10a34d65f507f6db01dd5a2acd4579d 100644 (file)
--- a/drivers/s390/scsi/zfcp_qdio.c
+++ b/drivers/s390/scsi/zfcp_qdio.c
@@ -4,7 +4,7 @@
  *
  * Setup and helper functions to access QDIO.
  *
- * Copyright IBM Corp. 2002, 2017
+ * Copyright IBM Corp. 2002, 2020
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -342,6 +342,18 @@ void zfcp_qdio_close(struct zfcp_qdio *qdio)
        atomic_set(&qdio->req_q_free, 0);
 }
 
+void zfcp_qdio_shost_update(struct zfcp_adapter *const adapter,
+                           const struct zfcp_qdio *const qdio)
+{
+       struct Scsi_Host *const shost = adapter->scsi_host;
+
+       if (shost == NULL)
+               return;
+
+       shost->sg_tablesize = qdio->max_sbale_per_req;
+       shost->max_sectors = qdio->max_sbale_per_req * 8;
+}
+
 /**
  * zfcp_qdio_open - prepare and initialize response queue
  * @qdio: pointer to struct zfcp_qdio
@@ -420,10 +432,7 @@ int zfcp_qdio_open(struct zfcp_qdio *qdio)
        atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q);
        atomic_or(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
 
-       if (adapter->scsi_host) {
-               adapter->scsi_host->sg_tablesize = qdio->max_sbale_per_req;
-               adapter->scsi_host->max_sectors = qdio->max_sbale_per_req * 8;
-       }
+       zfcp_qdio_shost_update(adapter, qdio);
 
        return 0;