From 0d9dc7c8b9b7fa0f53647423b41056ee1beed735 Mon Sep 17 00:00:00 2001 From: Gal Rosen Date: Thu, 21 Jan 2010 10:15:32 +0200 Subject: [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 Acked-by: James Smart Cc: Stable Tree Signed-off-by: James Bottomley --- drivers/scsi/scsi_transport_fc.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c index 79660ee3e211..1d5b72173dd8 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 -- cgit v1.2.3-59-g8ed1b