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path: root/drivers/s390/scsi
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Diffstat (limited to 'drivers/s390/scsi')
-rw-r--r--drivers/s390/scsi/zfcp_ext.h1
-rw-r--r--drivers/s390/scsi/zfcp_scsi.c9
-rw-r--r--drivers/s390/scsi/zfcp_sysfs.c55
-rw-r--r--drivers/s390/scsi/zfcp_unit.c8
4 files changed, 66 insertions, 7 deletions
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index c6acca521ffe..31e8a7240fd7 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -167,6 +167,7 @@ extern const struct attribute_group *zfcp_port_attr_groups[];
extern struct mutex zfcp_sysfs_port_units_mutex;
extern struct device_attribute *zfcp_sysfs_sdev_attrs[];
extern struct device_attribute *zfcp_sysfs_shost_attrs[];
+bool zfcp_sysfs_port_is_removing(const struct zfcp_port *const port);
/* zfcp_unit.c */
extern int zfcp_unit_add(struct zfcp_port *, u64);
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index 221d0dfb8493..e9ded2befa0d 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -129,6 +129,15 @@ static int zfcp_scsi_slave_alloc(struct scsi_device *sdev)
zfcp_sdev->erp_action.port = port;
+ mutex_lock(&zfcp_sysfs_port_units_mutex);
+ if (zfcp_sysfs_port_is_removing(port)) {
+ /* port is already gone */
+ mutex_unlock(&zfcp_sysfs_port_units_mutex);
+ put_device(&port->dev); /* undo zfcp_get_port_by_wwpn() */
+ return -ENXIO;
+ }
+ mutex_unlock(&zfcp_sysfs_port_units_mutex);
+
unit = zfcp_unit_find(port, zfcp_scsi_dev_lun(sdev));
if (unit)
put_device(&unit->dev);
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index b277be6f7611..af197e2b3e69 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -235,6 +235,53 @@ static ZFCP_DEV_ATTR(adapter, port_rescan, S_IWUSR, NULL,
DEFINE_MUTEX(zfcp_sysfs_port_units_mutex);
+static void zfcp_sysfs_port_set_removing(struct zfcp_port *const port)
+{
+ lockdep_assert_held(&zfcp_sysfs_port_units_mutex);
+ atomic_set(&port->units, -1);
+}
+
+bool zfcp_sysfs_port_is_removing(const struct zfcp_port *const port)
+{
+ lockdep_assert_held(&zfcp_sysfs_port_units_mutex);
+ return atomic_read(&port->units) == -1;
+}
+
+static bool zfcp_sysfs_port_in_use(struct zfcp_port *const port)
+{
+ struct zfcp_adapter *const adapter = port->adapter;
+ unsigned long flags;
+ struct scsi_device *sdev;
+ bool in_use = true;
+
+ mutex_lock(&zfcp_sysfs_port_units_mutex);
+ if (atomic_read(&port->units) > 0)
+ goto unlock_port_units_mutex; /* zfcp_unit(s) under port */
+
+ spin_lock_irqsave(adapter->scsi_host->host_lock, flags);
+ __shost_for_each_device(sdev, adapter->scsi_host) {
+ const struct zfcp_scsi_dev *zsdev = sdev_to_zfcp(sdev);
+
+ if (sdev->sdev_state == SDEV_DEL ||
+ sdev->sdev_state == SDEV_CANCEL)
+ continue;
+ if (zsdev->port != port)
+ continue;
+ /* alive scsi_device under port of interest */
+ goto unlock_host_lock;
+ }
+
+ /* port is about to be removed, so no more unit_add or slave_alloc */
+ zfcp_sysfs_port_set_removing(port);
+ in_use = false;
+
+unlock_host_lock:
+ spin_unlock_irqrestore(adapter->scsi_host->host_lock, flags);
+unlock_port_units_mutex:
+ mutex_unlock(&zfcp_sysfs_port_units_mutex);
+ return in_use;
+}
+
static ssize_t zfcp_sysfs_port_remove_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
@@ -257,15 +304,11 @@ static ssize_t zfcp_sysfs_port_remove_store(struct device *dev,
else
retval = 0;
- mutex_lock(&zfcp_sysfs_port_units_mutex);
- if (atomic_read(&port->units) > 0) {
+ if (zfcp_sysfs_port_in_use(port)) {
retval = -EBUSY;
- mutex_unlock(&zfcp_sysfs_port_units_mutex);
+ put_device(&port->dev); /* undo zfcp_get_port_by_wwpn() */
goto out;
}
- /* port is about to be removed, so no more unit_add */
- atomic_set(&port->units, -1);
- mutex_unlock(&zfcp_sysfs_port_units_mutex);
write_lock_irq(&adapter->port_list_lock);
list_del(&port->list);
diff --git a/drivers/s390/scsi/zfcp_unit.c b/drivers/s390/scsi/zfcp_unit.c
index 1bf0a0984a09..e67bf7388cae 100644
--- a/drivers/s390/scsi/zfcp_unit.c
+++ b/drivers/s390/scsi/zfcp_unit.c
@@ -124,7 +124,7 @@ int zfcp_unit_add(struct zfcp_port *port, u64 fcp_lun)
int retval = 0;
mutex_lock(&zfcp_sysfs_port_units_mutex);
- if (atomic_read(&port->units) == -1) {
+ if (zfcp_sysfs_port_is_removing(port)) {
/* port is already gone */
retval = -ENODEV;
goto out;
@@ -168,8 +168,14 @@ int zfcp_unit_add(struct zfcp_port *port, u64 fcp_lun)
write_lock_irq(&port->unit_list_lock);
list_add_tail(&unit->list, &port->unit_list);
write_unlock_irq(&port->unit_list_lock);
+ /*
+ * lock order: shost->scan_mutex before zfcp_sysfs_port_units_mutex
+ * due to zfcp_unit_scsi_scan() => zfcp_scsi_slave_alloc()
+ */
+ mutex_unlock(&zfcp_sysfs_port_units_mutex);
zfcp_unit_scsi_scan(unit);
+ return retval;
out:
mutex_unlock(&zfcp_sysfs_port_units_mutex);