scsi_debug: take sdebug_host_list_lock when changing capacity

All other traversals of the sdebug_host_list take the lock.

Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 2e32a4c09fbc..0d0e0593e3c5 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -4438,6 +4438,7 @@ static ssize_t virtual_gb_store(struct device_driver *ddp, const char *buf,
                         struct sdebug_host_info *sdhp;
                         struct sdebug_dev_info *dp;
 
+                        spin_lock(&sdebug_host_list_lock);
                         list_for_each_entry(sdhp, &sdebug_host_list,
                                             host_list) {
                                 list_for_each_entry(dp, &sdhp->dev_info_list,
@@ -4446,6 +4447,7 @@ static ssize_t virtual_gb_store(struct device_driver *ddp, const char *buf,
                                                 dp->uas_bm);
                                 }
                         }
+                        spin_unlock(&sdebug_host_list_lock);
                 }
                 return count;
         }