[34-longterm 125/179] libsas: remove expander from dev list on error

From: Paul Gortmaker
Date: Mon May 14 2012 - 22:41:38 EST

From: Luben Tuikov <ltuikov@xxxxxxxxx>

This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.

commit 5911e963d3718e306bcac387b83e259aa4228896 upstream.

If expander discovery fails (sas_discover_expander()), remove the
expander from the port device list (sas_ex_discover_expander()),
before freeing it. Else the list is corrupted and, e.g., when we
attempt to send SMP commands to other devices, the kernel oopses.

Signed-off-by: Luben Tuikov <ltuikov@xxxxxxxxx>
Reviewed-by: Jack Wang <jack_wang@xxxxxxxxx>
Signed-off-by: James Bottomley <JBottomley@xxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
drivers/scsi/libsas/sas_expander.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index c65af02..fbf0a09 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -841,6 +841,9 @@ static struct domain_device *sas_ex_discover_expander(

res = sas_discover_expander(child);
if (res) {
+ spin_lock_irq(&parent->port->dev_list_lock);
+ list_del(&child->dev_list_node);
+ spin_unlock_irq(&parent->port->dev_list_lock);
return NULL;

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