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[SCSI] zfcp: Change spin_lock_bh to spin_lock_irq to fix lockdep warning
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With the change to use the data on the SCSI device, iterating through
all LUNs/scsi_devices takes the SCSI host_lock. This triggers warnings
from the lock dependency checker:

=========================================================
[ INFO: possible irq lock inversion dependency detected ]
2.6.34.1 #97
---------------------------------------------------------
chchp/3224 just changed the state of lock:
 (&(shost->host_lock)->rlock){-.-...}, at: [<00000000003a73f4>] __scsi_iterate_devices+0x38/0xbc
but this lock took another, HARDIRQ-unsafe lock in the past:
 (&(&qdio->req_q_lock)->rlock){+.-...}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this: [   24.972394] 2 locks held by chchp/3224:
 #0:  (&(sch->lock)->rlock){-.-...}, at: [<0000000000401efa>] do_IRQ+0xb2/0x1e4
 #1:  (&adapter->port_list_lock){.-....}, at: [<0000000000490302>] zfcp_erp_modify_adapter_status+0x9e/0x16c
[...]

=========================================================
[ INFO: possible irq lock inversion dependency detected ]
2.6.34.1 #98
---------------------------------------------------------
chchp/3235 just changed the state of lock:
 (&(shost->host_lock)->rlock){-.-...}, at: [<00000000003a73f4>] __scsi_iterate_devices+0x38/0xbc
but this lock took another, HARDIRQ-unsafe lock in the past:
 (&(&qdio->stat_lock)->rlock){+.-...}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
2 locks held by chchp/3235:
 #0:  (&(sch->lock)->rlock){-.-...}, at: [<0000000000401efa>] do_IRQ+0xb2/0x1e4
 #1:  (&adapter->port_list_lock){.-.-..}, at: [<00000000004902f6>] zfcp_erp_modify_adapter_status+0x9e/0x16c
[...]

To stop this warning, change the request queue lock to disable irqs,
not only softirq. The changes are required only outside of the
critical "send fcp command" path.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
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Christof Schmitt authored and James Bottomley committed Sep 17, 2010
1 parent f8210e3 commit 44a24cb
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Showing 2 changed files with 46 additions and 44 deletions.
72 changes: 36 additions & 36 deletions drivers/s390/scsi/zfcp_fsf.c
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Original file line number Diff line number Diff line change
Expand Up @@ -773,7 +773,7 @@ int zfcp_fsf_status_read(struct zfcp_qdio *qdio)
struct fsf_status_read_buffer *sr_buf;
int retval = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand Down Expand Up @@ -807,7 +807,7 @@ int zfcp_fsf_status_read(struct zfcp_qdio *qdio)
zfcp_fsf_req_free(req);
zfcp_dbf_hba_fsf_unsol("fail", adapter->dbf, NULL);
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand Down Expand Up @@ -876,7 +876,7 @@ struct zfcp_fsf_req *zfcp_fsf_abort_fcp_cmnd(struct scsi_cmnd *scmnd)
struct zfcp_qdio *qdio = zfcp_sdev->port->adapter->qdio;
unsigned long old_req_id = (unsigned long) scmnd->host_scribble;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;
req = zfcp_fsf_req_create(qdio, FSF_QTCB_ABORT_FCP_CMND,
Expand Down Expand Up @@ -907,7 +907,7 @@ struct zfcp_fsf_req *zfcp_fsf_abort_fcp_cmnd(struct scsi_cmnd *scmnd)
zfcp_fsf_req_free(req);
req = NULL;
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return req;
}

Expand Down Expand Up @@ -1046,7 +1046,7 @@ int zfcp_fsf_send_ct(struct zfcp_fc_wka_port *wka_port,
struct zfcp_fsf_req *req;
int ret = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand Down Expand Up @@ -1078,7 +1078,7 @@ int zfcp_fsf_send_ct(struct zfcp_fc_wka_port *wka_port,
failed_send:
zfcp_fsf_req_free(req);
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return ret;
}

Expand Down Expand Up @@ -1142,7 +1142,7 @@ int zfcp_fsf_send_els(struct zfcp_adapter *adapter, u32 d_id,
struct zfcp_qdio *qdio = adapter->qdio;
int ret = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand Down Expand Up @@ -1178,7 +1178,7 @@ int zfcp_fsf_send_els(struct zfcp_adapter *adapter, u32 d_id,
failed_send:
zfcp_fsf_req_free(req);
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return ret;
}

Expand All @@ -1188,7 +1188,7 @@ int zfcp_fsf_exchange_config_data(struct zfcp_erp_action *erp_action)
struct zfcp_qdio *qdio = erp_action->adapter->qdio;
int retval = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand Down Expand Up @@ -1220,7 +1220,7 @@ int zfcp_fsf_exchange_config_data(struct zfcp_erp_action *erp_action)
erp_action->fsf_req_id = 0;
}
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand All @@ -1230,7 +1230,7 @@ int zfcp_fsf_exchange_config_data_sync(struct zfcp_qdio *qdio,
struct zfcp_fsf_req *req = NULL;
int retval = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out_unlock;

Expand All @@ -1256,15 +1256,15 @@ int zfcp_fsf_exchange_config_data_sync(struct zfcp_qdio *qdio,

zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
retval = zfcp_fsf_req_send(req);
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
if (!retval)
wait_for_completion(&req->completion);

zfcp_fsf_req_free(req);
return retval;

out_unlock:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand All @@ -1282,7 +1282,7 @@ int zfcp_fsf_exchange_port_data(struct zfcp_erp_action *erp_action)
if (!(qdio->adapter->adapter_features & FSF_FEATURE_HBAAPI_MANAGEMENT))
return -EOPNOTSUPP;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand All @@ -1309,7 +1309,7 @@ int zfcp_fsf_exchange_port_data(struct zfcp_erp_action *erp_action)
erp_action->fsf_req_id = 0;
}
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand All @@ -1328,7 +1328,7 @@ int zfcp_fsf_exchange_port_data_sync(struct zfcp_qdio *qdio,
if (!(qdio->adapter->adapter_features & FSF_FEATURE_HBAAPI_MANAGEMENT))
return -EOPNOTSUPP;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out_unlock;

Expand All @@ -1348,7 +1348,7 @@ int zfcp_fsf_exchange_port_data_sync(struct zfcp_qdio *qdio,
req->handler = zfcp_fsf_exchange_port_data_handler;
zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
retval = zfcp_fsf_req_send(req);
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);

if (!retval)
wait_for_completion(&req->completion);
Expand All @@ -1358,7 +1358,7 @@ int zfcp_fsf_exchange_port_data_sync(struct zfcp_qdio *qdio,
return retval;

out_unlock:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand Down Expand Up @@ -1442,7 +1442,7 @@ int zfcp_fsf_open_port(struct zfcp_erp_action *erp_action)
struct zfcp_fsf_req *req;
int retval = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand Down Expand Up @@ -1473,7 +1473,7 @@ int zfcp_fsf_open_port(struct zfcp_erp_action *erp_action)
put_device(&port->dev);
}
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand Down Expand Up @@ -1510,7 +1510,7 @@ int zfcp_fsf_close_port(struct zfcp_erp_action *erp_action)
struct zfcp_fsf_req *req;
int retval = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand Down Expand Up @@ -1539,7 +1539,7 @@ int zfcp_fsf_close_port(struct zfcp_erp_action *erp_action)
erp_action->fsf_req_id = 0;
}
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand Down Expand Up @@ -1585,7 +1585,7 @@ int zfcp_fsf_open_wka_port(struct zfcp_fc_wka_port *wka_port)
struct zfcp_fsf_req *req;
int retval = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand All @@ -1610,7 +1610,7 @@ int zfcp_fsf_open_wka_port(struct zfcp_fc_wka_port *wka_port)
if (retval)
zfcp_fsf_req_free(req);
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand Down Expand Up @@ -1638,7 +1638,7 @@ int zfcp_fsf_close_wka_port(struct zfcp_fc_wka_port *wka_port)
struct zfcp_fsf_req *req;
int retval = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand All @@ -1663,7 +1663,7 @@ int zfcp_fsf_close_wka_port(struct zfcp_fc_wka_port *wka_port)
if (retval)
zfcp_fsf_req_free(req);
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand Down Expand Up @@ -1728,7 +1728,7 @@ int zfcp_fsf_close_physical_port(struct zfcp_erp_action *erp_action)
struct zfcp_fsf_req *req;
int retval = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand Down Expand Up @@ -1757,7 +1757,7 @@ int zfcp_fsf_close_physical_port(struct zfcp_erp_action *erp_action)
erp_action->fsf_req_id = 0;
}
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand Down Expand Up @@ -1900,7 +1900,7 @@ int zfcp_fsf_open_lun(struct zfcp_erp_action *erp_action)
struct zfcp_fsf_req *req;
int retval = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand Down Expand Up @@ -1933,7 +1933,7 @@ int zfcp_fsf_open_lun(struct zfcp_erp_action *erp_action)
erp_action->fsf_req_id = 0;
}
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand Down Expand Up @@ -1987,7 +1987,7 @@ int zfcp_fsf_close_lun(struct zfcp_erp_action *erp_action)
struct zfcp_fsf_req *req;
int retval = -EIO;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand Down Expand Up @@ -2017,7 +2017,7 @@ int zfcp_fsf_close_lun(struct zfcp_erp_action *erp_action)
erp_action->fsf_req_id = 0;
}
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return retval;
}

Expand Down Expand Up @@ -2363,7 +2363,7 @@ struct zfcp_fsf_req *zfcp_fsf_fcp_task_mgmt(struct scsi_cmnd *scmnd,
ZFCP_STATUS_COMMON_UNBLOCKED)))
return NULL;

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand Down Expand Up @@ -2397,7 +2397,7 @@ struct zfcp_fsf_req *zfcp_fsf_fcp_task_mgmt(struct scsi_cmnd *scmnd,
zfcp_fsf_req_free(req);
req = NULL;
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);
return req;
}

Expand Down Expand Up @@ -2433,7 +2433,7 @@ struct zfcp_fsf_req *zfcp_fsf_control_file(struct zfcp_adapter *adapter,
return ERR_PTR(-EINVAL);
}

spin_lock_bh(&qdio->req_q_lock);
spin_lock_irq(&qdio->req_q_lock);
if (zfcp_qdio_sbal_get(qdio))
goto out;

Expand All @@ -2460,7 +2460,7 @@ struct zfcp_fsf_req *zfcp_fsf_control_file(struct zfcp_adapter *adapter,
zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
retval = zfcp_fsf_req_send(req);
out:
spin_unlock_bh(&qdio->req_q_lock);
spin_unlock_irq(&qdio->req_q_lock);

if (!retval) {
wait_for_completion(&req->completion);
Expand Down
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