[PATCH] fix vlsi_ir.c compile if !CONFIG_PROC_FS

On Mon, 9 Jun 2003, Jean Tourrilhes wrote:

> > Yes, Thanks. In fact walking over the proc-stuff in vlsi_ir, there are
> > some more places which need cleanup and fixing.
> >
> > Jean, please apply the patch below - ChangeLog:
>
> 	Would you mind sending it also to Jeff ? I want you to be able
> to work without depending on me.
> 	But I'll add that on my todo list anyway...

Ok - here we go. Slightly improved patch compared to what I've sent first
so we handle now failure in create_proc_entry and !CONFIG_PROC_FS
identical, i.e. continue without proc entry. It's not needed for the
driver to work.

Updated Changelog:

* make it compile without CONFIG_PROC_FS (problem reported by Adrian Bunk,
  original patch by Sam Ravnborg)
* get rid of a number of unneeded ifdef/endif CONFIG_PROC_FS (also
  removing an "unused label" warning)
* use proc entrys' owner fields to protect against module removal racing
  with proc entry access.
* handle failure in create_proc_entry like !CONFIG_PROC_FS
* set driver version 0.4a

Jeff, would please forward it for application to 2.5!

Martin

drivers/net/irda/vlsi_ir.c

@@ -2,7 +2,7 @@
  *
  *	vlsi_ir.c:	VLSI82C147 PCI IrDA controller driver for Linux
  *
- *	Copyright (c) 2001-2002 Martin Diehl
+ *	Copyright (c) 2001-2003 Martin Diehl
  *
  *	This program is free software; you can redistribute it and/or 
  *	modify it under the terms of the GNU General Public License as 
@@ -28,7 +28,7 @@ MODULE_AUTHOR("Martin Diehl <info@mdiehl.de>");
 MODULE_LICENSE("GPL");
 
 #define DRIVER_NAME "vlsi_ir"
-#define DRIVER_VERSION "v0.4"
+#define DRIVER_VERSION "v0.4a"
 
 /********************************************************/
 
@@ -149,6 +149,9 @@ static void vlsi_ring_debug(struct vlsi_ring *r)
 
 /********************************************************/
 
+/* needed regardless of CONFIG_PROC_FS */
+static struct proc_dir_entry *vlsi_proc_root = NULL;
+
 #ifdef CONFIG_PROC_FS
 
 static int vlsi_proc_pdev(struct pci_dev *pdev, char *buf, int len)
@@ -394,8 +397,6 @@ static int vlsi_proc_print(struct net_device *ndev, char *buf, int len)
 	return out - buf;
 }
 
-static struct proc_dir_entry *vlsi_proc_root = NULL;
-
 struct vlsi_proc_data {
 	int size;
 	char *data;
@@ -494,11 +495,18 @@ static int vlsi_proc_release(struct inode *inode, struct file *file)
 }
 
 static struct file_operations vlsi_proc_fops = {
+	/* protect individual procdir file entry against rmmod */
+	.owner		= THIS_MODULE,
 	.open		= vlsi_proc_open,
 	.llseek		= vlsi_proc_lseek,
 	.read		= vlsi_proc_read,
 	.release	= vlsi_proc_release,
 };
+
+#define VLSI_PROC_FOPS		(&vlsi_proc_fops)
+
+#else	/* CONFIG_PROC_FS */
+#define VLSI_PROC_FOPS		NULL
 #endif
 
 /********************************************************/
@@ -1800,8 +1808,7 @@ vlsi_irda_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		goto out_freedev;
 	}
 
-#ifdef CONFIG_PROC_FS
-	{
+	if (vlsi_proc_root != NULL) {
 		struct proc_dir_entry *ent;
 
 		ent = create_proc_entry(ndev->name, S_IFREG|S_IRUGO, vlsi_proc_root);
@@ -1810,11 +1817,11 @@ vlsi_irda_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 			goto out_unregister;
 		}
 		ent->data = ndev;
-		ent->proc_fops = &vlsi_proc_fops;
+		ent->proc_fops = VLSI_PROC_FOPS;
 		ent->size = 0;
 		idev->proc_entry = ent;
-	}
-#endif
+	} else
+		idev->proc_entry = NULL;
 
 	printk(KERN_INFO "%s: registered device %s\n", drivername, ndev->name);
 
@@ -1851,12 +1858,10 @@ static void __devexit vlsi_irda_remove(struct pci_dev *pdev)
 	down(&idev->sem);
 	pci_set_drvdata(pdev, NULL);
 	pci_disable_device(pdev);
-#ifdef CONFIG_PROC_FS
 	if (idev->proc_entry) {
 		remove_proc_entry(ndev->name, vlsi_proc_root);
 		idev->proc_entry = NULL;
 	}
-#endif
 	up(&idev->sem);
 
 	unregister_netdev(ndev);
@@ -1993,9 +1998,7 @@ static struct pci_driver vlsi_irda_driver = {
 #endif
 };
 
-#ifdef CONFIG_PROC_FS
 #define PROC_DIR ("driver/" DRIVER_NAME)
-#endif
 
 static int __init vlsi_mod_init(void)
 {
@@ -2025,18 +2028,23 @@ static int __init vlsi_mod_init(void)
 
 	sirpulse = !!sirpulse;
 
-#ifdef CONFIG_PROC_FS
+	/* create_proc_entry returns NULL if !CONFIG_PROC_FS.
+	 * Failure to create the procfs entry is handled like running
+	 * without procfs - it's not required for the driver to work.
+	 */
 	vlsi_proc_root = create_proc_entry(PROC_DIR, S_IFDIR, 0);
-	if (!vlsi_proc_root)
-		return -ENOMEM;
-#endif
+	if (vlsi_proc_root) {
+		/* protect registered procdir against module removal.
+		 * Because we are in the module init path there's no race
+		 * window after create_proc_entry (and no barrier needed).
+		 */
+		vlsi_proc_root->owner = THIS_MODULE;
+	}
 
 	ret = pci_module_init(&vlsi_irda_driver);
 
-#ifdef CONFIG_PROC_FS
-	if (ret)
+	if (ret && vlsi_proc_root)
 		remove_proc_entry(PROC_DIR, 0);
-#endif
 	return ret;
 
 }
@@ -2044,6 +2052,7 @@ static int __init vlsi_mod_init(void)
 static void __exit vlsi_mod_exit(void)
 {
 	pci_unregister_driver(&vlsi_irda_driver);
+	if (vlsi_proc_root)
 		remove_proc_entry(PROC_DIR, 0);
 }
 

include/net/irda/vlsi_ir.h

@@ -3,9 +3,9 @@
  *
  *	vlsi_ir.h:	VLSI82C147 PCI IrDA controller driver for Linux
  *
- *	Version:	0.4
+ *	Version:	0.4a
  *
- *	Copyright (c) 2001-2002 Martin Diehl
+ *	Copyright (c) 2001-2003 Martin Diehl
  *
  *	This program is free software; you can redistribute it and/or 
  *	modify it under the terms of the GNU General Public License as 
@@ -730,9 +730,7 @@ typedef struct vlsi_irda_dev {
 
 	u32			cfg_space[64/sizeof(u32)];
 	u8			resume_ok;	
-#ifdef CONFIG_PROC_FS
 	struct proc_dir_entry	*proc_entry;
-#endif
 
 } vlsi_irda_dev_t;