diff options
Diffstat (limited to 'include/linux/debugfs.h')
| -rw-r--r-- | include/linux/debugfs.h | 62 |
1 files changed, 58 insertions, 4 deletions
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index 0928a6c8ae1e..59444b495d49 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -71,9 +71,63 @@ typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *); struct dentry *debugfs_lookup(const char *name, struct dentry *parent); -struct dentry *debugfs_create_file(const char *name, umode_t mode, - struct dentry *parent, void *data, - const struct file_operations *fops); +struct debugfs_short_fops { + ssize_t (*read)(struct file *, char __user *, size_t, loff_t *); + ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *); + loff_t (*llseek) (struct file *, loff_t, int); +}; + +struct dentry *debugfs_create_file_full(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct file_operations *fops); +struct dentry *debugfs_create_file_short(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct debugfs_short_fops *fops); + +/** + * debugfs_create_file - create a file in the debugfs filesystem + * @name: a pointer to a string containing the name of the file to create. + * @mode: the permission that the file should have. + * @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. + * @data: a pointer to something that the caller will want to get to later + * on. The inode.i_private pointer will point to this value on + * the open() call. + * @fops: a pointer to a struct file_operations or struct debugfs_short_fops that + * should be used for this file. + * + * This is the basic "create a file" function for debugfs. It allows for a + * wide range of flexibility in creating a file, or a directory (if you want + * to create a directory, the debugfs_create_dir() function is + * recommended to be used instead.) + * + * This function will return a pointer to a dentry if it succeeds. This + * pointer must be passed to the debugfs_remove() function when the file is + * to be removed (no automatic cleanup happens if your module is unloaded, + * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will be + * returned. + * + * If debugfs is not enabled in the kernel, the value -%ENODEV will be + * returned. + * + * If fops points to a struct debugfs_short_fops, then simple_open() will be + * used for the open, and only read/write/llseek are supported and are proxied, + * so no module reference or release are needed. + * + * NOTE: it's expected that most callers should _ignore_ the errors returned + * by this function. Other debugfs functions handle the fact that the "dentry" + * passed to them could be an error and they don't crash in that case. + * Drivers should generally work fine even if debugfs fails to init anyway. + */ +#define debugfs_create_file(name, mode, parent, data, fops) \ + _Generic(fops, \ + const struct file_operations *: debugfs_create_file_full, \ + const struct debugfs_short_fops *: debugfs_create_file_short, \ + struct file_operations *: debugfs_create_file_full, \ + struct debugfs_short_fops *: debugfs_create_file_short) \ + (name, mode, parent, data, fops) + struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops); @@ -207,7 +261,7 @@ static inline struct dentry *debugfs_lookup(const char *name, static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, - const struct file_operations *fops) + const void *fops) { return ERR_PTR(-ENODEV); } |