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authorSteffen Maier <maier@linux.vnet.ibm.com>2013-04-26 17:34:54 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-28 16:18:51 -0700
commit9cfe5af116d3c10595733f11681399f5d80980f6 (patch)
treee29e74d3c4a23480906caa8874a9bdae94bbffbc
parente5056425dd86e1e8cc8411014daec42a408483d8 (diff)
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> [sm: Backported to 3.0: - Copyright notice changed slightly - Don't use zfcp_fsf_convert_portspeed()] 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.c21
2 files changed, 19 insertions, 7 deletions
diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 61da2cd22508..fc669c00b722 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 Corporation 2002, 2010
+ * Copyright IBM Corp. 2002, 2013
*/
/*
@@ -23,6 +23,7 @@
* Christof Schmitt
* Martin Petermann
* Sven Schuetz
+ * Steffen Maier
*/
#define KMSG_COMPONENT "zfcp"
@@ -414,6 +415,8 @@ 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 8976d0238097..ceb7f7c2dedd 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 Corporation 2002, 2010
+ * Copyright IBM Corp. 2002, 2013
*/
#define KMSG_COMPONENT "zfcp"
@@ -455,11 +455,8 @@ 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) = 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);
@@ -467,6 +464,18 @@ 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) = 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);
@@ -488,8 +497,6 @@ static int zfcp_fsf_exchange_config_evaluate(struct zfcp_fsf_req *req)
return -EIO;
}
- zfcp_scsi_set_prot(adapter);
-
return 0;
}
@@ -540,6 +547,8 @@ 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");