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authorSteffen Maier <maier@linux.vnet.ibm.com>2013-04-26 19:34:54 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-26 01:07:30 +0400
commit8f425c63ecda1bab9982892e7890041292e2d5ec (patch)
treed27c45b027b1f31832b5a895582137c361fb6afd
parentb22b8386992d886aa487b57e000b18512e639710 (diff)
downloadlinux-8f425c63ecda1bab9982892e7890041292e2d5ec.tar.xz
SCSI: zfcp: status read buffers on first adapter open with link down
commit 9edf7d75ee5f21663a0183d21f702682d0ef132f upstream. Commit 64deb6efdc5504ce97b5c1c6f281fffbc150bd93 "[SCSI] zfcp: Use status_read_buf_num provided by FCP channel" started using a value returned by the channel but only evaluated the value if the fabric link is up. Commit 8d88cf3f3b9af4713642caeb221b6d6a42019001 "[SCSI] zfcp: Update status read mempool" introduced mempool resizings based on the above value. On setting an FCP device online for the very first time since boot, a new zeroed adapter object is allocated. If the link is down, the number of status read requests remains zero. Since just the config data exchange is incomplete, we proceed with adapter open recovery. However, we unconditionally call mempool_resize with adapter->stat_read_buf_num == 0 in this case. This causes a kernel message "kernel BUG at mm/mempool.c:131!" in process "zfcperp<FCP-device-bus-ID>" with last function mempool_resize in Krnl PSW and zfcp_erp_thread in the Call Trace. Don't evaluate channel values which are invalid on link down. The number of status read requests is always valid, evaluated, and set to a positive minimum greater than zero. The adapter open recovery can proceed and the channel has status read buffers to inform us on a future link up event. While we are not aware of any other code path that could result in mempool resize attempts of size zero, we still also initialize the number of status read buffers to be posted to a static minimum number on adapter object allocation. Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/s390/scsi/zfcp_aux.c5
-rw-r--r--drivers/s390/scsi/zfcp_fsf.c23
2 files changed, 20 insertions, 8 deletions
diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index f6adde44f226..3743ac931231 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -3,7 +3,7 @@
*
* Module interface and handling of zfcp data structures.
*
- * Copyright IBM Corp. 2002, 2010
+ * Copyright IBM Corp. 2002, 2013
*/
/*
@@ -23,6 +23,7 @@
* Christof Schmitt
* Martin Petermann
* Sven Schuetz
+ * Steffen Maier
*/
#define KMSG_COMPONENT "zfcp"
@@ -415,6 +416,8 @@ struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
adapter->dma_parms.max_segment_size = ZFCP_QDIO_SBALE_LEN;
adapter->ccw_device->dev.dma_parms = &adapter->dma_parms;
+ adapter->stat_read_buf_num = FSF_STATUS_READS_RECOM;
+
if (!zfcp_scsi_adapter_register(adapter))
return adapter;
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 06760e435259..9152999a0707 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -3,7 +3,7 @@
*
* Implementation of FSF commands.
*
- * Copyright IBM Corp. 2002, 2010
+ * Copyright IBM Corp. 2002, 2013
*/
#define KMSG_COMPONENT "zfcp"
@@ -483,12 +483,8 @@ static int zfcp_fsf_exchange_config_evaluate(struct zfcp_fsf_req *req)
fc_host_port_name(shost) = nsp->fl_wwpn;
fc_host_node_name(shost) = nsp->fl_wwnn;
- fc_host_port_id(shost) = ntoh24(bottom->s_id);
- fc_host_speed(shost) =
- zfcp_fsf_convert_portspeed(bottom->fc_link_speed);
fc_host_supported_classes(shost) = FC_COS_CLASS2 | FC_COS_CLASS3;
- adapter->hydra_version = bottom->adapter_type;
adapter->timer_ticks = bottom->timer_interval & ZFCP_FSF_TIMER_INT_MASK;
adapter->stat_read_buf_num = max(bottom->status_read_buf_num,
(u16)FSF_STATUS_READS_RECOM);
@@ -496,6 +492,19 @@ static int zfcp_fsf_exchange_config_evaluate(struct zfcp_fsf_req *req)
if (fc_host_permanent_port_name(shost) == -1)
fc_host_permanent_port_name(shost) = fc_host_port_name(shost);
+ zfcp_scsi_set_prot(adapter);
+
+ /* no error return above here, otherwise must fix call chains */
+ /* do not evaluate invalid fields */
+ if (req->qtcb->header.fsf_status == FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE)
+ return 0;
+
+ fc_host_port_id(shost) = ntoh24(bottom->s_id);
+ fc_host_speed(shost) =
+ zfcp_fsf_convert_portspeed(bottom->fc_link_speed);
+
+ adapter->hydra_version = bottom->adapter_type;
+
switch (bottom->fc_topology) {
case FSF_TOPO_P2P:
adapter->peer_d_id = ntoh24(bottom->peer_d_id);
@@ -517,8 +526,6 @@ static int zfcp_fsf_exchange_config_evaluate(struct zfcp_fsf_req *req)
return -EIO;
}
- zfcp_scsi_set_prot(adapter);
-
return 0;
}
@@ -569,6 +576,8 @@ static void zfcp_fsf_exchange_config_data_handler(struct zfcp_fsf_req *req)
&adapter->status);
zfcp_fsf_link_down_info_eval(req,
&qtcb->header.fsf_status_qual.link_down_info);
+ if (zfcp_fsf_exchange_config_evaluate(req))
+ return;
break;
default:
zfcp_erp_adapter_shutdown(adapter, 0, "fsecdh3");