Exported devfs_find_and_unregister() and devfs_only() to modules

Updated README from master HTML file
Fixed module unload race in devfs_open()

Documentation/filesystems/devfs/ChangeLog

@@ -1957,3 +1957,11 @@ Changes for patch v216
   <devfs_get_handle>
 
 - Removed deprecated <devfs_find_handle>
+===============================================================================
+Changes for patch v217
+
+- Exported <devfs_find_and_unregister> and <devfs_only> to modules
+
+- Updated README from master HTML file
+
+- Fixed module unload race in <devfs_open>

Documentation/filesystems/devfs/README

@@ -3,7 +3,7 @@ Devfs (Device File System) FAQ
 
 Linux Devfs (Device File System) FAQ
 Richard Gooch
-21-JUL-2002
+20-AUG-2002
 
 
 Document languages:
@@ -1509,6 +1509,16 @@ Here are some common questions and answers.
 
 
 
+Devfsd doesn't start
+
+Make sure you have compiled and installed devfsd
+Make sure devfsd is being started from your boot
+scripts
+Make sure you have configured your kernel to enable devfs (see
+below)
+Make sure devfs is mounted (see below)
+
+
 Devfsd is not managing all my permissions
 
 Make sure you are capturing the appropriate events. For example,
@@ -1777,7 +1787,7 @@ I hate the naming scheme
 First, remember that no naming scheme will please everybody. You hate
 the scheme, others love it. Who's to say who's right and who's wrong?
 Ultimately, the person who writes the code gets to choose, and what
-exists now is a combination of the the choices made by the
+exists now is a combination of the choices made by the
 devfs author and the
 kernel maintainer (Linus).
 

fs/devfs/base.c

@@ -645,6 +645,9 @@
     20020728   Richard Gooch <rgooch@atnf.csiro.au>
 	       Removed deprecated <devfs_find_handle>.
   v1.20
+    20020820   Richard Gooch <rgooch@atnf.csiro.au>
+	       Fixed module unload race in <devfs_open>.
+  v1.21
 */
 #include <linux/types.h>
 #include <linux/errno.h>
@@ -677,7 +680,7 @@
 #include <asm/bitops.h>
 #include <asm/atomic.h>
 
-#define DEVFS_VERSION            "1.20 (20020728)"
+#define DEVFS_VERSION            "1.21 (20020820)"
 
 #define DEVFS_NAME "devfs"
 
@@ -2232,6 +2235,7 @@ const char *devfs_get_name (devfs_handle_t de, unsigned int *namelen)
  *
  *	If "devfs=only" this function will return 1, otherwise 0 is returned.
  */
+
 int devfs_only (void)
 {
     return (boot_options & OPTION_ONLY) ? 1 : 0;
@@ -2382,7 +2386,7 @@ static int check_disc_changed (struct devfs_entry *de)
     extern int warn_no_part;
 
     if ( !S_ISBLK (de->mode) ) return 0;
-    bdev = bdget(kdev_t_to_nr(dev));
+    bdev = bdget (kdev_t_to_nr (dev) );
     if (!bdev) return 0;
     bdops = devfs_get_ops (de);
     if (!bdops) return 0;
@@ -2390,7 +2394,7 @@ static int check_disc_changed (struct devfs_entry *de)
     /*  Ugly hack to disable messages about unable to read partition table  */
     tmp = warn_no_part;
     warn_no_part = 0;
-    retval = full_check_disk_change(bdev);
+    retval = full_check_disk_change (bdev);
     warn_no_part = tmp;
 out:
     devfs_put_ops (de);
@@ -2692,21 +2696,23 @@ static int devfs_open (struct inode *inode, struct file *file)
     struct fcb_type *df;
     struct devfs_entry *de;
     struct fs_info *fs_info = inode->i_sb->u.generic_sbp;
+    void *ops;
 
     de = get_devfs_entry_from_vfs_inode (inode);
     if (de == NULL) return -ENODEV;
     if ( S_ISDIR (de->mode) ) return 0;
     df = &de->u.fcb;
     file->private_data = de->info;
+    ops = devfs_get_ops (de);  /*  Now have module refcount  */
     if ( S_ISBLK (inode->i_mode) )
     {
 	file->f_op = &def_blk_fops;
-	if (df->ops) inode->i_bdev->bd_op = df->ops;
-	err = def_blk_fops.open (inode, file);
+	if (ops) inode->i_bdev->bd_op = ops;
+	err = def_blk_fops.open (inode, file); /* Module refcount unchanged */
     }
     else
     {
-	file->f_op = fops_get ( (struct file_operations *) df->ops );
+	file->f_op = ops;
 	if (file->f_op)
 	{
 	    lock_kernel ();
@@ -2714,7 +2720,7 @@ static int devfs_open (struct inode *inode, struct file *file)
 	    unlock_kernel ();
 	}
 	else
-	{   /*  Fallback to legacy scheme  */
+	{   /*  Fallback to legacy scheme (I don't have a module refcount)  */
 	    if ( S_ISCHR (inode->i_mode) ) err = chrdev_open (inode, file);
 	    else err = -ENODEV;
 	}