libfs: add simple_open()

debugfs and a few other drivers use an open-coded version of simple_open() to pass a pointer from the file to the read/write file ops. Add support for this simple case to libfs so that we can remove the many duplicate copies of this simple function. Signed-off-by: Stephen Boyd <[email protected]> Cc: Al Viro <[email protected]> Cc: Julia Lawall <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
klaby · Apr 5, 2012 · 20955e8 · 20955e8
1 parent 7563ec4
commit 20955e8
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diff --git a/fs/libfs.c b/fs/libfs.c
@@ -264,6 +264,13 @@ struct dentry *mount_pseudo(struct file_system_type *fs_type, char *name,
 	return ERR_PTR(-ENOMEM);
 }
 
+int simple_open(struct inode *inode, struct file *file)
+{
+	if (inode->i_private)
+		file->private_data = inode->i_private;
+	return 0;
+}
+
 int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
 {
 	struct inode *inode = old_dentry->d_inode;
@@ -984,6 +991,7 @@ EXPORT_SYMBOL(simple_dir_operations);
 EXPORT_SYMBOL(simple_empty);
 EXPORT_SYMBOL(simple_fill_super);
 EXPORT_SYMBOL(simple_getattr);
+EXPORT_SYMBOL(simple_open);
 EXPORT_SYMBOL(simple_link);
 EXPORT_SYMBOL(simple_lookup);
 EXPORT_SYMBOL(simple_pin_fs);

diff --git a/include/linux/fs.h b/include/linux/fs.h
@@ -2502,6 +2502,7 @@ extern int dcache_readdir(struct file *, void *, filldir_t);
 extern int simple_setattr(struct dentry *, struct iattr *);
 extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
 extern int simple_statfs(struct dentry *, struct kstatfs *);
+extern int simple_open(struct inode *inode, struct file *file);
 extern int simple_link(struct dentry *, struct inode *, struct dentry *);
 extern int simple_unlink(struct inode *, struct dentry *);
 extern int simple_rmdir(struct inode *, struct dentry *);