fops: sh -x is fun

Author: cirosantilli

README.adoc

@@ -3010,6 +3010,14 @@ Sources:
 * link:kernel_module/fops.c[]
 * link:rootfs_overlay/fops.sh[]
 
+Then give this a try:
+
+....
+sh -x /fops.sh
+....
+
+We have put printks on each fop, so this allows you to see which system calls are being made for each command.
+
 File operations is the main method of userland driver communication.
 
 `struct file_operations` determines what the kernel will do on filesystem system calls of <<pseudo-filesystems>>.