From 0078bff5283d1fd6417b840eda6dab912b7a5560 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 29 Apr 2011 00:24:29 +0200 Subject: Allow setting of number of raw devices as a module parameter Allow setting of maximal number of raw devices as a module parameter. This requires changing of static array into a vmalloced one (the array is going to be too large for kmalloc). Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- drivers/char/Kconfig | 2 +- drivers/char/raw.c | 33 +++++++++++++++++++++++++++------ 2 files changed, 28 insertions(+), 7 deletions(-) diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index ad59b4e..49502bc 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -523,7 +523,7 @@ config RAW_DRIVER with the O_DIRECT flag. config MAX_RAW_DEVS - int "Maximum number of RAW devices to support (1-8192)" + int "Maximum number of RAW devices to support (1-65536)" depends on RAW_DRIVER default "256" help diff --git a/drivers/char/raw.c b/drivers/char/raw.c index b4b9d5a..6f9db62 100644 --- a/drivers/char/raw.c +++ b/drivers/char/raw.c @@ -21,6 +21,7 @@ #include #include #include +#include #include @@ -30,10 +31,15 @@ struct raw_device_data { }; static struct class *raw_class; -static struct raw_device_data raw_devices[MAX_RAW_MINORS]; +static struct raw_device_data *raw_devices; static DEFINE_MUTEX(raw_mutex); static const struct file_operations raw_ctl_fops; /* forward declaration */ +static int max_raw_minors = MAX_RAW_MINORS; + +module_param(max_raw_minors, int, 0); +MODULE_PARM_DESC(max_raw_minors, "Maximum number of raw devices (1-65536)"); + /* * Open/close code for raw IO. * @@ -125,7 +131,7 @@ static int bind_set(int number, u64 major, u64 minor) struct raw_device_data *rawdev; int err = 0; - if (number <= 0 || number >= MAX_RAW_MINORS) + if (number <= 0 || number >= max_raw_minors) return -EINVAL; if (MAJOR(dev) != major || MINOR(dev) != minor) @@ -312,12 +318,26 @@ static int __init raw_init(void) dev_t dev = MKDEV(RAW_MAJOR, 0); int ret; - ret = register_chrdev_region(dev, MAX_RAW_MINORS, "raw"); + if (max_raw_minors < 1 || max_raw_minors > 65536) { + printk(KERN_WARNING "raw: invalid max_raw_minors (must be" + " between 1 and 65536), using %d\n", MAX_RAW_MINORS); + max_raw_minors = MAX_RAW_MINORS; + } + + raw_devices = vmalloc(sizeof(struct raw_device_data) * max_raw_minors); + if (!raw_devices) { + printk(KERN_ERR "Not enough memory for raw device structures\n"); + ret = -ENOMEM; + goto error; + } + memset(raw_devices, 0, sizeof(struct raw_device_data) * max_raw_minors); + + ret = register_chrdev_region(dev, max_raw_minors, "raw"); if (ret) goto error; cdev_init(&raw_cdev, &raw_fops); - ret = cdev_add(&raw_cdev, dev, MAX_RAW_MINORS); + ret = cdev_add(&raw_cdev, dev, max_raw_minors); if (ret) { kobject_put(&raw_cdev.kobj); goto error_region; @@ -336,8 +356,9 @@ static int __init raw_init(void) return 0; error_region: - unregister_chrdev_region(dev, MAX_RAW_MINORS); + unregister_chrdev_region(dev, max_raw_minors); error: + vfree(raw_devices); return ret; } @@ -346,7 +367,7 @@ static void __exit raw_exit(void) device_destroy(raw_class, MKDEV(RAW_MAJOR, 0)); class_destroy(raw_class); cdev_del(&raw_cdev); - unregister_chrdev_region(MKDEV(RAW_MAJOR, 0), MAX_RAW_MINORS); + unregister_chrdev_region(MKDEV(RAW_MAJOR, 0), max_raw_minors); } module_init(raw_init); -- cgit v1.1