Merge pull request #74 from Mu2e/eflumerf/ChownDevFile

Label device file with current user

Author: ron003

mu2e_driver/mu2e_fs.c

@@ -41,6 +41,7 @@ struct cdev mu2e_cdev;
 
 static int mu2e_dtc_count[MU2E_MAX_NUM_DTCS] = {0};
 static kuid_t mu2e_dtc_owner[MU2E_MAX_NUM_DTCS] = {{0}};
+static kuid_t root_uid = {{0}};
 static DEFINE_SPINLOCK(mu2e_fs_spinlock);
 
 int mu2e_fs_up()
@@ -98,7 +99,11 @@ int mu2e_open(struct inode *inode, struct file *filp)
 	}
 
 	if (mu2e_dtc_count[dtc] == 0)
+	{
 		mu2e_dtc_owner[dtc] = current_uid(); /* grab it */
+		inode->i_uid = current_uid();
+		mark_inode_dirty(inode);
+	}
 
 	mu2e_dtc_count[dtc]++;
 	spin_unlock(&mu2e_fs_spinlock);
@@ -111,6 +116,11 @@ int mu2e_release(struct inode *inode, struct file *filp)
 	int dtc = iminor(inode);
 	spin_lock(&mu2e_fs_spinlock);
 	mu2e_dtc_count[dtc]--;
+	if (mu2e_dtc_count[dtc] == 0)
+	{
+		inode->i_uid = root_uid;
+		mark_inode_dirty(inode);
+    }
 	spin_unlock(&mu2e_fs_spinlock);
 	return 0;
 }