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authorGal Rosen <galr@storwize.com>2010-01-21 10:15:32 +0200
committerJames Bottomley <James.Bottomley@suse.de>2010-03-08 22:36:53 +0530
commit0d9dc7c8b9b7fa0f53647423b41056ee1beed735 (patch)
tree19cab2c6559f6cc5a31abfcf4fc1e33b0528ebc7
parentd55f88f0275e4b21435957d3d354a79bb9edeec7 (diff)
[SCSI] scsi_transport_fc: Fix synchronization issue while deleting vport
The issue occur while deleting 60 virtual ports through the sys interface /sys/class/fc_vports/vport-X/vport_delete. It happen while in a mistake each request sent twice for the same vport. This interface is asynchronous, entering the delete request into a work queue, allowing more than one request to enter to the delete work queue. The result is a NULL pointer. The first request already delete the vport, while the second request got a pointer to the vport before the device destroyed. Re-create vport later cause system freeze. Solution: Check vport flags before entering the request to the work queue. [jejb: fixed int<->long problem on spinlock flags variable] Signed-off-by: Gal Rosen <galr@storwize.com> Acked-by: James Smart <james.smart@emulex.com> Cc: Stable Tree <stable@kernel.org> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
-rw-r--r--drivers/scsi/scsi_transport_fc.c24
1 files changed, 12 insertions, 12 deletions
diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 79660ee3e21..1d5b72173dd 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -1232,6 +1232,15 @@ store_fc_vport_delete(struct device *dev, struct device_attribute *attr,
{
struct fc_vport *vport = transport_class_to_vport(dev);
struct Scsi_Host *shost = vport_to_shost(vport);
+ unsigned long flags;
+
+ spin_lock_irqsave(shost->host_lock, flags);
+ if (vport->flags & (FC_VPORT_DEL | FC_VPORT_CREATING)) {
+ spin_unlock_irqrestore(shost->host_lock, flags);
+ return -EBUSY;
+ }
+ vport->flags |= FC_VPORT_DELETING;
+ spin_unlock_irqrestore(shost->host_lock, flags);
fc_queue_work(shost, &vport->vport_delete_work);
return count;
@@ -1821,6 +1830,9 @@ store_fc_host_vport_delete(struct device *dev, struct device_attribute *attr,
list_for_each_entry(vport, &fc_host->vports, peers) {
if ((vport->channel == 0) &&
(vport->port_name == wwpn) && (vport->node_name == wwnn)) {
+ if (vport->flags & (FC_VPORT_DEL | FC_VPORT_CREATING))
+ break;
+ vport->flags |= FC_VPORT_DELETING;
match = 1;
break;
}
@@ -3370,18 +3382,6 @@ fc_vport_terminate(struct fc_vport *vport)
unsigned long flags;
int stat;
- spin_lock_irqsave(shost->host_lock, flags);
- if (vport->flags & FC_VPORT_CREATING) {
- spin_unlock_irqrestore(shost->host_lock, flags);
- return -EBUSY;
- }
- if (vport->flags & (FC_VPORT_DEL)) {
- spin_unlock_irqrestore(shost->host_lock, flags);
- return -EALREADY;
- }
- vport->flags |= FC_VPORT_DELETING;
- spin_unlock_irqrestore(shost->host_lock, flags);
-
if (i->f->vport_delete)
stat = i->f->vport_delete(vport);
else