Don't lock out the driver when root is accessing it

Mu2e · Jan 13, 2025 · 1eda004 · 1eda004
1 parent d2b3dfa
commit 1eda004
Showing 1 changed file with 11 additions and 0 deletions.
diff --git a/mu2e_driver/mu2e_fs.c b/mu2e_driver/mu2e_fs.c
@@ -86,6 +86,10 @@ void mu2e_fs_down()
 
 int mu2e_open(struct inode *inode, struct file *filp)
 {
+    // Root doesn't have to ask for permission, and shouldn't lock out anyone
+    if (capable(CAP_DAC_OVERRIDE)) {
+		return 0;
+    }
 	int dtc = iminor(inode);
 
 	spin_lock(&mu2e_fs_spinlock);
@@ -114,6 +118,13 @@ int mu2e_open(struct inode *inode, struct file *filp)
 int mu2e_release(struct inode *inode, struct file *filp)
 {
 	int dtc = iminor(inode);
+
+	// Root doesn't have to ask for permission, and shouldn't lock out anyone
+	if (capable(CAP_DAC_OVERRIDE))
+	{
+		return 0;
+	}
+
 	spin_lock(&mu2e_fs_spinlock);
 	mu2e_dtc_count[dtc]--;
 	if (mu2e_dtc_count[dtc] == 0)