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-core.c b/drivers/ata/libata-core.c
index e0bda9ff89cd..28db50b57b91 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -95,7 +95,7 @@ static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
 static void ata_dev_xfermask(struct ata_device *dev);
 static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
 
-unsigned int ata_print_id = 1;
+atomic_t ata_print_id = ATOMIC_INIT(1);
 
 struct ata_force_param {
         const char      *name;
@@ -6029,7 +6029,7 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
 
         /* give ports names and add SCSI hosts */
         for (i = 0; i < host->n_ports; i++)
-                host->ports[i]->print_id = ata_print_id++;
+                host->ports[i]->print_id = atomic_inc_return(&ata_print_id);
 
 
         /* Create associated sysfs transport objects  */