Use the race free function for adding a proc file.

[cascardo/kernel/samples/03.proc/.git] / hello_procfs.c

diff --git a/hello_procfs.c b/hello_procfs.c
index a78eff8..5e0e082 100644 (file)
--- a/hello_procfs.c
+++ b/hello_procfs.c
@@ -18,47 +18,28 @@
 
 
 #include <linux/module.h>
+/* Needed for procfs register functions */
 #include <linux/proc_fs.h>
+/* Needed for using the seq_file infrastructure */
 #include <linux/seq_file.h>
 
 MODULE_AUTHOR("Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>");
 MODULE_LICENSE("GPL");
 
+/* write our message to the sequential file */
 static int hello_show(struct seq_file *file, void *data)
 {
        seq_puts(file, "Hello, world!\n");
        return 0;
 }
 
-#if 0
-static void * hello_start(struct seq_file *file, loff_t *pos)
-{
-       return NULL;
-}
-
-static void hello_stop(struct seq_file *file, void *data)
-{
-}
-
-static void * hello_next(struct seq_file *file, void *data, loff_t *pos)
-{
-       return NULL;
-}
-
-static const struct seq_operations hello_seqops =
-{
-       .start = hello_start,
-       .stop = hello_stop,
-       .next = hello_next,
-       .show = hello_show,
-};
-#endif
-
+/* use the single sequential file */
 static int hello_procfs_open(struct inode *inode, struct file *file)
 {
        return single_open(file, hello_show, NULL);
 }
 
+/* our file operations use the seq_file stuff to make it an easy task */
 static const struct file_operations hello_procfs_fops =
 {
        .open = hello_procfs_open,
@@ -69,15 +50,17 @@ static const struct file_operations hello_procfs_fops =
 
 static int hello_procfs_init(void)
 {
+       /* create the proc entry and set its fops: there is a potential race
+        * here */
        struct proc_dir_entry *entry;
-       entry = create_proc_entry("gnu", 0666, NULL);
-       entry->proc_fops = &hello_procfs_fops;
+       entry = proc_create("hellop", 0666, NULL, &hello_procfs_fops);
        return 0;
 }
 
 static void hello_procfs_exit(void)
 {
-       remove_proc_entry("gnu", NULL);
+       /* remove our proc entry */
+       remove_proc_entry("hellop", NULL);
 }
 
 module_init(hello_procfs_init);