xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

[SCSI] libsas: fix port->dev_list locking

Browse Source 
port->dev_list maintains a list of devices attached to a given sas root port.
It needs to be mutated under a lock as contexts outside of the
single-threaded-libsas-workqueue access the list via sas_find_dev_by_rphy().
Fixup locations where the list was being mutated without a lock.

This is a follow-up to commit 5911e963 "[SCSI] libsas: remove expander
from dev list on error", where Luben noted [1]:

    > 2/ We have unlocked list manipulations in sas_ex_discover_end_dev(),
    > sas_unregister_common_dev(), and sas_ex_discover_end_dev()

    Yes, I can see that and that is very unfortunate.

[1]: http://marc.info/?l=linux-scsi&m=131480962006471&w=2

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Dan Williams
2011-09-21 22:05:34 -07:00
committed by James Bottomley
parent 29f366e8a9
commit 1a34c06401
3 changed files with 18 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/scsi/libsas/sas_discover.c
View File

@@ -219,17 +219,20 @@ out_err2:
/* ---------- Device registration and unregistration ---------- */
static inline void sas_unregister_common_dev(struct domain_device *dev)
static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_device *dev)
{
sas_notify_lldd_dev_gone(dev);
if (!dev->parent)
dev->port->port_dev = NULL;
else
list_del_init(&dev->siblings);
spin_lock_irq(&port->dev_list_lock);
list_del_init(&dev->dev_list_node);
spin_unlock_irq(&port->dev_list_lock);
}
void sas_unregister_dev(struct domain_device *dev)
void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
{
if (dev->rphy) {
sas_remove_children(&dev->rphy->dev);
@@ -241,15 +244,15 @@ void sas_unregister_dev(struct domain_device *dev)
kfree(dev->ex_dev.ex_phy);
dev->ex_dev.ex_phy = NULL;
}
sas_unregister_common_dev(dev);
sas_unregister_common_dev(port, dev);
}
void sas_unregister_domain_devices(struct asd_sas_port *port)
{
struct domain_device *dev, *n;
list_for_each_entry_safe_reverse(dev,n,&port->dev_list,dev_list_node)
sas_unregister_dev(dev);
list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node)
sas_unregister_dev(port, dev);
port->port->rphy = NULL;