[SCSI] scsi_transport_fc: Fix synchronization issue while deleting vport (0d9dc7c8) · Commits · 戴 / test

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>

drivers/scsi/scsi_transport_fc.c

+12 −12

Original line number	Diff line number	Diff line
		@@ -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

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