From 7c8d469877b16d2c1cecf101a0abb7b218db85bc Mon Sep 17 00:00:00 2001 From: Nicolai Stange Date: Tue, 31 Oct 2017 00:15:47 +0100 Subject: debugfs: add support for more elaborate ->d_fsdata Currently, the user provided fops, "real_fops", are stored directly into ->d_fsdata. In order to be able to store more per-file state and thus prepare for more granular file removal protection, wrap the real_fops into a dynamically allocated container struct, debugfs_fsdata. A struct debugfs_fsdata gets allocated at file creation and freed from the newly intoduced ->d_release(). Finally, move the implementation of debugfs_real_fops() out of the public debugfs header such that struct debugfs_fsdata's declaration can be kept private. Signed-off-by: Nicolai Stange Signed-off-by: Greg Kroah-Hartman --- include/linux/debugfs.h | 20 +++----------------- 1 file changed, 3 insertions(+), 17 deletions(-) (limited to 'include/linux/debugfs.h') diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index b93efc8feecd..cbee5f4a02a3 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -45,23 +45,6 @@ extern struct dentry *arch_debugfs_dir; extern struct srcu_struct debugfs_srcu; -/** - * debugfs_real_fops - getter for the real file operation - * @filp: a pointer to a struct file - * - * Must only be called under the protection established by - * debugfs_use_file_start(). - */ -static inline const struct file_operations *debugfs_real_fops(const struct file *filp) - __must_hold(&debugfs_srcu) -{ - /* - * Neither the pointer to the struct file_operations, nor its - * contents ever change -- srcu_dereference() is not needed here. - */ - return filp->f_path.dentry->d_fsdata; -} - #define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \ static int __fops ## _open(struct inode *inode, struct file *file) \ { \ @@ -112,6 +95,9 @@ int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx) void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu); +const struct file_operations *debugfs_real_fops(const struct file *filp) + __must_hold(&debugfs_srcu); + ssize_t debugfs_attr_read(struct file *file, char __user *buf, size_t len, loff_t *ppos); ssize_t debugfs_attr_write(struct file *file, const char __user *buf, -- cgit