[SCSI] zfcp: remove unit will fail if add unit is not finished

On some hardware it can take some time to add a unit. If
some remove this unit during this process the remove will
fail.

Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 15 insertions, 6 deletions

diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index 9a3b8e261c0a..3e51e64d1108 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -254,12 +254,21 @@ static ssize_t zfcp_sysfs_unit_remove_store(struct device *dev,
 
         write_lock_irq(&zfcp_data.config_lock);
         unit = zfcp_get_unit_by_lun(port, fcp_lun);
-        if (unit && (atomic_read(&unit->refcount) == 0)) {
-                zfcp_unit_get(unit);
-                atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
-                list_move(&unit->list, &unit_remove_lh);
-        } else
-                unit = NULL;
+        if (unit) {
+                write_unlock_irq(&zfcp_data.config_lock);
+                /* wait for possible timeout during SCSI probe */
+                flush_work(&unit->scsi_work);
+                write_lock_irq(&zfcp_data.config_lock);
+
+                if (atomic_read(&unit->refcount) == 0) {
+                        zfcp_unit_get(unit);
+                        atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE,
+                                        &unit->status);
+                        list_move(&unit->list, &unit_remove_lh);
+                } else {
+                        unit = NULL;
+                }
+        }
 
         write_unlock_irq(&zfcp_data.config_lock);