libata: make ata_print_id atomic

This variable is incremented from multiple contexts (module_init via
libata-lldds and the libsas discovery thread).  Make it atomic to head
off any chance of libsas and libata creating duplicate ids.

Acked-by: Jacek Danecki <jacek.danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 1ee00c8b5b04..93dabdcd2cbe 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3843,7 +3843,7 @@ int ata_sas_async_port_init(struct ata_port *ap)
         int rc = ap->ops->port_start(ap);
 
         if (!rc) {
-                ap->print_id = ata_print_id++;
+                ap->print_id = atomic_inc_return(&ata_print_id);
                 __ata_port_probe(ap);
         }
 
@@ -3867,7 +3867,7 @@ int ata_sas_port_init(struct ata_port *ap)
         int rc = ap->ops->port_start(ap);
 
         if (!rc) {
-                ap->print_id = ata_print_id++;
+                ap->print_id = atomic_inc_return(&ata_print_id);
                 rc = ata_port_probe(ap);
         }