[S390] dcssblk: fix race in dcssblk_add_store()
Concurrently adding the same segment may lead to duplicate device_register()
calls, which will trigger an error in kobject code:
"... don't try to register things with the same name in the same directory".
This patch adds a check to avoid this.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 01fcdd9..db85f1f 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -384,6 +384,10 @@
* get minor, add to list
*/
down_write(&dcssblk_devices_sem);
+ if (dcssblk_get_segment_by_name(local_buf)) {
+ rc = -EEXIST;
+ goto release_gd;
+ }
rc = dcssblk_assign_free_minor(dev_info);
if (rc) {
up_write(&dcssblk_devices_sem);