[PATCH RFC v3 06/22] scsi: libsas: Improve sas_ex_discover_expander() error handling

John Garry
2022-10-25T09:50:00Z

Errors in function sas_ex_discover_expander() are generally ignored, so add
handling to gracefully handles errors in all cases.

Signed-off-by: John Garry <john.garry@huawei.com>
---
drivers/scsi/libsas/sas_expander.c | 50 ++++++++++++++++++++----------
1 file changed, 34 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 2907ca5d0ed4..9e33014ec412 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -919,7 +919,6 @@ static struct domain_device *sas_ex_discover_expander(
struct sas_rphy *rphy;
struct sas_expander_device *edev;
struct asd_sas_port *port;
- int res;

if (phy->routing_attr == DIRECT_ROUTING) {
pr_warn("ex %016llx:%02d:D <--> ex %016llx:0x%x is not allowed\n",
@@ -933,9 +932,11 @@ static struct domain_device *sas_ex_discover_expander(
return NULL;

phy->port = sas_port_alloc(&parent->rphy->dev, phy_id);
- /* FIXME: better error handling */
- BUG_ON(sas_port_add(phy->port) != 0);
+ if (!phy->port)
+ goto err_put_child;

+ if (!sas_port_add(phy->port))
+ goto err_delete_port;

switch (phy->attached_dev_type) {
case SAS_EDGE_EXPANDER_DEVICE:
@@ -948,8 +949,15 @@ static struct domain_device *sas_ex_discover_expander(
break;
default:
rphy = NULL; /* shut gcc up */
- BUG();
+ pr_warn("ex unhandled dev type %d %016llx:%02d:D <--> ex %016llx:%02d\n",
+ phy->attached_dev_type,
+ SAS_ADDR(parent->sas_addr), phy_id,
+ SAS_ADDR(phy->attached_sas_addr),
+ phy->attached_phy_id);
}
+ if (!rphy)
+ goto err_free_port;
+
port = parent->port;
child->rphy = rphy;
get_device(&rphy->dev);
@@ -967,26 +975,36 @@ static struct domain_device *sas_ex_discover_expander(
parent->port->disc.max_level = max(parent->port->disc.max_level,
edev->level);
sas_init_dev(child);
+
sas_fill_in_rphy(child, rphy);
- sas_rphy_add(rphy);
+ if (!sas_rphy_add(rphy))
+ goto err_rphy_free;

spin_lock_irq(&parent->port->dev_list_lock);
list_add_tail(&child->dev_list_node, &parent->port->dev_list);
spin_unlock_irq(&parent->port->dev_list_lock);

- res = sas_discover_expander(child);
- if (res) {
- sas_rphy_delete(rphy);
- spin_lock_irq(&parent->port->dev_list_lock);
- list_del(&child->dev_list_node);
- spin_unlock_irq(&parent->port->dev_list_lock);
- sas_put_device(child);
- sas_port_delete(phy->port);
- phy->port = NULL;
- return NULL;
- }
+ if (!sas_discover_expander(child))
+ goto err_rphy_remove;
+
list_add_tail(&child->siblings, &parent->ex_dev.children);
return child;
+
+err_rphy_remove:
+ spin_lock_irq(&parent->port->dev_list_lock);
+ list_del(&child->dev_list_node);
+ spin_unlock_irq(&parent->port->dev_list_lock);
+ sas_rphy_remove(rphy);
+err_rphy_free:
+ sas_rphy_free(rphy);
+err_free_port:
+ sas_port_free(phy->port);
+err_delete_port:
+ sas_port_delete(phy->port);
+ phy->port = NULL;
+err_put_child:
+ sas_put_device(child);
+ return NULL;
}

static int sas_ex_discover_dev(struct domain_device *dev, int phy_id)
--
2.35.3