As of now, a miscdevice driver has to provide an implementation of the open() file operation if it wants to have misc_open() assign a pointer to struct miscdevice to file->private_data for other file operations to use (given the user calls open()).
This leads to situations where a miscdevice driver that doesn't need internal operations during open() has to implement open() that only returns immediately, in order to use the data in private_data in other fops. This provides consistent behaviour for miscdevice developers and will always provide the pointer in private_data. A driver's open() fop would, of course, just overwrite it, when using private_data itself. Signed-off-by: Martin Kepplinger <mart...@posteo.de> --- drivers/char/misc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/misc.c b/drivers/char/misc.c index ffa97d2..205ad4c 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -142,8 +142,8 @@ static int misc_open(struct inode * inode, struct file * file) err = 0; replace_fops(file, new_fops); + file->private_data = c; if (file->f_op->open) { - file->private_data = c; err = file->f_op->open(inode,file); } fail: -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/