new primitive: debugfs_create_automount()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 1219dff..957c40c 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -175,6 +175,18 @@
.show_options = debugfs_show_options,
};
+static struct vfsmount *debugfs_automount(struct path *path)
+{
+ struct vfsmount *(*f)(void *);
+ f = (struct vfsmount *(*)(void *))path->dentry->d_fsdata;
+ return f(path->dentry->d_inode->i_private);
+}
+
+static const struct dentry_operations debugfs_dops = {
+ .d_delete = always_delete_dentry,
+ .d_automount = debugfs_automount,
+};
+
static int debug_fill_super(struct super_block *sb, void *data, int silent)
{
static struct tree_descr debug_files[] = {{""}};
@@ -199,6 +211,7 @@
goto fail;
sb->s_op = &debugfs_super_operations;
+ sb->s_d_op = &debugfs_dops;
debugfs_apply_options(sb);
@@ -368,6 +381,41 @@
EXPORT_SYMBOL_GPL(debugfs_create_dir);
/**
+ * debugfs_create_automount - create automount point in the debugfs filesystem
+ * @name: a pointer to a string containing the name of the file to create.
+ * @parent: a pointer to the parent dentry for this file. This should be a
+ * directory dentry if set. If this parameter is NULL, then the
+ * file will be created in the root of the debugfs filesystem.
+ * @f: function to be called when pathname resolution steps on that one.
+ * @data: opaque argument to pass to f().
+ *
+ * @f should return what ->d_automount() would.
+ */
+struct dentry *debugfs_create_automount(const char *name,
+ struct dentry *parent,
+ struct vfsmount *(*f)(void *),
+ void *data)
+{
+ struct dentry *dentry = start_creating(name, parent);
+ struct inode *inode;
+
+ if (IS_ERR(dentry))
+ return NULL;
+
+ inode = debugfs_get_inode(dentry->d_sb);
+ if (unlikely(!inode))
+ return failed_creating(dentry);
+
+ inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
+ inode->i_flags |= S_AUTOMOUNT;
+ inode->i_private = data;
+ dentry->d_fsdata = (void *)f;
+ d_instantiate(dentry, inode);
+ return end_creating(dentry);
+}
+EXPORT_SYMBOL(debugfs_create_automount);
+
+/**
* debugfs_create_symlink- create a symbolic link in the debugfs filesystem
* @name: a pointer to a string containing the name of the symbolic link to
* create.
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index da4c498..ea149a2 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -56,6 +56,11 @@
struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
const char *dest);
+struct dentry *debugfs_create_automount(const char *name,
+ struct dentry *parent,
+ struct vfsmount *(*f)(void *),
+ void *data);
+
void debugfs_remove(struct dentry *dentry);
void debugfs_remove_recursive(struct dentry *dentry);