src/patches/suse-2.6.27.39/patches.suse/raw_device_max_minors_param.diff

   1 From: Jan Kara <jack@suse.cz>
   2 Subject: Allow setting of number of raw devices as a module parameter
   3 References: FATE 302178
   4 Patch-mainline: never
   5
   6 Allow setting of maximal number of raw devices as a module parameter. This requires
   7 changing of static array into a vmalloced one (the array is going to be too large
   8 for kmalloc).
   9
  10 Signed-off-by: Jan Kara <jack@suse.cz>
  11
  12 ---
  13  drivers/char/Kconfig |    2 +-
  14  drivers/char/raw.c   |   33 +++++++++++++++++++++++++++------
  15  2 files changed, 28 insertions(+), 7 deletions(-)
  16
  17 --- a/drivers/char/Kconfig
  18 +++ b/drivers/char/Kconfig
  19 @@ -1026,7 +1026,7 @@ config RAW_DRIVER
  20            with the O_DIRECT flag.
  21
  22  config MAX_RAW_DEVS
  23 -       int "Maximum number of RAW devices to support (1-8192)"
  24 +       int "Maximum number of RAW devices to support (1-65536)"
  25         depends on RAW_DRIVER
  26         default "256"
  27         help
  28 --- a/drivers/char/raw.c
  29 +++ b/drivers/char/raw.c
  30 @@ -20,6 +20,7 @@
  31  #include <linux/device.h>
  32  #include <linux/mutex.h>
  33  #include <linux/smp_lock.h>
  34 +#include <linux/vmalloc.h>
  35
  36  #include <asm/uaccess.h>
  37
  38 @@ -29,10 +30,15 @@ struct raw_device_data {
  39  };
  40
  41  static struct class *raw_class;
  42 -static struct raw_device_data raw_devices[MAX_RAW_MINORS];
  43 +static struct raw_device_data *raw_devices;
  44  static DEFINE_MUTEX(raw_mutex);
  45  static const struct file_operations raw_ctl_fops; /* forward declaration */
  46
  47 +static int max_raw_minors = MAX_RAW_MINORS;
  48 +
  49 +module_param(max_raw_minors, int, 0);
  50 +MODULE_PARM_DESC(max_raw_minors, "Maximum number of raw devices (1-65536)");
  51 +
  52  /*
  53   * Open/close code for raw IO.
  54   *
  55 @@ -158,7 +164,7 @@ static int raw_ctl_ioctl(struct inode *i
  56                         goto out;
  57                 }
  58
  59 -               if (rq.raw_minor <= 0 || rq.raw_minor >= MAX_RAW_MINORS) {
  60 +               if (rq.raw_minor <= 0 || rq.raw_minor >= max_raw_minors) {
  61                         err = -EINVAL;
  62                         goto out;
  63                 }
  64 @@ -266,12 +272,26 @@ static int __init raw_init(void)
  65         dev_t dev = MKDEV(RAW_MAJOR, 0);
  66         int ret;
  67
  68 -       ret = register_chrdev_region(dev, MAX_RAW_MINORS, "raw");
  69 +       if (max_raw_minors < 1 || max_raw_minors > 65536) {
  70 +               printk(KERN_WARNING "raw: invalid max_raw_minors (must be"
  71 +                       " between 1 and 65536), using %d\n", MAX_RAW_MINORS);
  72 +               max_raw_minors = MAX_RAW_MINORS;
  73 +       }
  74 +
  75 +       raw_devices = vmalloc(sizeof(struct raw_device_data) * max_raw_minors);
  76 +       if (!raw_devices) {
  77 +               printk(KERN_ERR "Not enough memory for raw device structures\n");
  78 +               ret = -ENOMEM;
  79 +               goto error;
  80 +       }
  81 +       memset(raw_devices, 0, sizeof(struct raw_device_data) * max_raw_minors);
  82 +
  83 +       ret = register_chrdev_region(dev, max_raw_minors, "raw");
  84         if (ret)
  85                 goto error;
  86
  87         cdev_init(&raw_cdev, &raw_fops);
  88 -       ret = cdev_add(&raw_cdev, dev, MAX_RAW_MINORS);
  89 +       ret = cdev_add(&raw_cdev, dev, max_raw_minors);
  90         if (ret) {
  91                 kobject_put(&raw_cdev.kobj);
  92                 goto error_region;
  93 @@ -290,8 +310,9 @@ static int __init raw_init(void)
  94         return 0;
  95
  96  error_region:
  97 -       unregister_chrdev_region(dev, MAX_RAW_MINORS);
  98 +       unregister_chrdev_region(dev, max_raw_minors);
  99  error:
 100 +       vfree(raw_devices);
 101         return ret;
 102  }
 103
 104 @@ -300,7 +321,7 @@ static void __exit raw_exit(void)
 105         device_destroy(raw_class, MKDEV(RAW_MAJOR, 0));
 106         class_destroy(raw_class);
 107         cdev_del(&raw_cdev);
 108 -       unregister_chrdev_region(MKDEV(RAW_MAJOR, 0), MAX_RAW_MINORS);
 109 +       unregister_chrdev_region(MKDEV(RAW_MAJOR, 0), max_raw_minors);
 110  }
 111
 112  module_init(raw_init);