Merge branch 'debugfs_automount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull debugfs patches from Al Viro:
 "debugfs patches, mostly to make it possible for something like tracefs
  to be transparently automounted on given directory in debugfs.

  New primitive in there is debugfs_create_automount(name, parent, func,
  arg), which creates a directory and makes its ->d_automount() return
  func(arg).  Another missing primitive was debugfs_create_file_size() -
  open-coded in quite a few places.  Dave's patch adds it and converts
  the open-code instances to calling it"

* 'debugfs_automount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  debugfs: Provide a file creation function that also takes an initial size
  new primitive: debugfs_create_automount()
  debugfs: split end_creating() into success and failure cases
  debugfs: take mode-dependent parts of debugfs_get_inode() into callers
  fold debugfs_mknod() into callers
  fold debugfs_create() into caller
  fold debugfs_mkdir() into caller
  debugfs_mknod(): get rid useless arguments
  fold debugfs_link() into caller
  debugfs: kill __create_file()
  debugfs: split the beginning and the end of __create_file() off
  debugfs_{mkdir,create,link}(): get rid of redundant argument

drivers/infiniband/hw/cxgb4/device.c

@@ -700,37 +700,24 @@ static const struct file_operations ep_debugfs_fops = {
 
 static int setup_debugfs(struct c4iw_dev *devp)
 {
-	struct dentry *de;
-
 	if (!devp->debugfs_root)
 		return -1;
 
-	de = debugfs_create_file("qps", S_IWUSR, devp->debugfs_root,
-				 (void *)devp, &qp_debugfs_fops);
-	if (de && de->d_inode)
-		de->d_inode->i_size = 4096;
+	debugfs_create_file_size("qps", S_IWUSR, devp->debugfs_root,
+				 (void *)devp, &qp_debugfs_fops, 4096);
 
-	de = debugfs_create_file("stags", S_IWUSR, devp->debugfs_root,
-				 (void *)devp, &stag_debugfs_fops);
-	if (de && de->d_inode)
-		de->d_inode->i_size = 4096;
+	debugfs_create_file_size("stags", S_IWUSR, devp->debugfs_root,
+				 (void *)devp, &stag_debugfs_fops, 4096);
 
-	de = debugfs_create_file("stats", S_IWUSR, devp->debugfs_root,
-			(void *)devp, &stats_debugfs_fops);
-	if (de && de->d_inode)
-		de->d_inode->i_size = 4096;
+	debugfs_create_file_size("stats", S_IWUSR, devp->debugfs_root,
+				 (void *)devp, &stats_debugfs_fops, 4096);
 
-	de = debugfs_create_file("eps", S_IWUSR, devp->debugfs_root,
-			(void *)devp, &ep_debugfs_fops);
-	if (de && de->d_inode)
-		de->d_inode->i_size = 4096;
+	debugfs_create_file_size("eps", S_IWUSR, devp->debugfs_root,
+				 (void *)devp, &ep_debugfs_fops, 4096);
 
-	if (c4iw_wr_log) {
-		de = debugfs_create_file("wr_log", S_IWUSR, devp->debugfs_root,
-					 (void *)devp, &wr_log_debugfs_fops);
-		if (de && de->d_inode)
-			de->d_inode->i_size = 4096;
-	}
+	if (c4iw_wr_log)
+		debugfs_create_file_size("wr_log", S_IWUSR, devp->debugfs_root,
+					 (void *)devp, &wr_log_debugfs_fops, 4096);
 	return 0;
 }
 

drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c

@@ -1950,12 +1950,9 @@ static void set_debugfs_file_size(struct dentry *de, loff_t size)
 static void add_debugfs_mem(struct adapter *adap, const char *name,
 			    unsigned int idx, unsigned int size_mb)
 {
-	struct dentry *de;
-
-	de = debugfs_create_file(name, S_IRUSR, adap->debugfs_root,
-				 (void *)adap + idx, &mem_debugfs_fops);
-	if (de && de->d_inode)
-		de->d_inode->i_size = size_mb << 20;
+	debugfs_create_file_size(name, S_IRUSR, adap->debugfs_root,
+				 (void *)adap + idx, &mem_debugfs_fops,
+				 size_mb << 20);
 }
 
 /* Add an array of Debug FS files.

drivers/scsi/csiostor/csio_init.c

@@ -113,12 +113,9 @@ static const struct file_operations csio_mem_debugfs_fops = {
 void csio_add_debugfs_mem(struct csio_hw *hw, const char *name,
 				 unsigned int idx, unsigned int size_mb)
 {
-	struct dentry *de;
-
-	de = debugfs_create_file(name, S_IRUSR, hw->debugfs_root,
-				 (void *)hw + idx, &csio_mem_debugfs_fops);
-	if (de && de->d_inode)
-		de->d_inode->i_size = size_mb << 20;
+	debugfs_create_file_size(name, S_IRUSR, hw->debugfs_root,
+				 (void *)hw + idx, &csio_mem_debugfs_fops,
+				 size_mb << 20);
 }
 
 static int csio_setup_debugfs(struct csio_hw *hw)

drivers/usb/gadget/udc/atmel_usba_udc.c

@@ -265,14 +265,17 @@ static void usba_init_debugfs(struct usba_udc *udc)
 		goto err_root;
 	udc->debugfs_root = root;
 
-	regs = debugfs_create_file("regs", 0400, root, udc, &regs_dbg_fops);
-	if (!regs)
-		goto err_regs;
-
 	regs_resource = platform_get_resource(udc->pdev, IORESOURCE_MEM,
 				CTRL_IOMEM_ID);
-	regs->d_inode->i_size = resource_size(regs_resource);
-	udc->debugfs_regs = regs;
+
+	if (regs_resource) {
+		regs = debugfs_create_file_size("regs", 0400, root, udc,
+						&regs_dbg_fops,
+						resource_size(regs_resource));
+		if (!regs)
+			goto err_regs;
+		udc->debugfs_regs = regs;
+	}
 
 	usba_ep_init_debugfs(udc, to_usba_ep(udc->gadget.ep0));
 

include/linux/debugfs.h

@@ -51,11 +51,21 @@ struct dentry *debugfs_create_file(const char *name, umode_t mode,
 				   struct dentry *parent, void *data,
 				   const struct file_operations *fops);
 
+struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
+					struct dentry *parent, void *data,
+					const struct file_operations *fops,
+					loff_t file_size);
+
 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
 
 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);
 
@@ -124,6 +134,14 @@ static inline struct dentry *debugfs_create_file(const char *name, umode_t mode,
 	return ERR_PTR(-ENODEV);
 }
 
+static inline struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
+					struct dentry *parent, void *data,
+					const struct file_operations *fops,
+					loff_t file_size)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 static inline struct dentry *debugfs_create_dir(const char *name,
 						struct dentry *parent)
 {