git.oblomov.eu Git - linux-2.6/blob - drivers/s390/block/dasd_ioctl.c

   1 /*
   2  * File...........: linux/drivers/s390/block/dasd_ioctl.c
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
   9  *
  10  * i/o controls for the dasd driver.
  11  */
  12 #include <linux/config.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/major.h>
  15 #include <linux/fs.h>
  16 #include <linux/blkpg.h>
  17
  18 #include <asm/ccwdev.h>
  19 #include <asm/uaccess.h>
  20
  21 /* This is ugly... */
  22 #define PRINTK_HEADER "dasd_ioctl:"
  23
  24 #include "dasd_int.h"
  25
  26 /*
  27  * SECTION: ioctl functions.
  28  */
  29 static struct list_head dasd_ioctl_list = LIST_HEAD_INIT(dasd_ioctl_list);
  30
  31 /*
  32  * Find the ioctl with number no.
  33  */
  34 static struct dasd_ioctl *
  35 dasd_find_ioctl(int no)
  36 {
  37         struct dasd_ioctl *ioctl;
  38
  39         list_for_each_entry (ioctl, &dasd_ioctl_list, list)
  40                 if (ioctl->no == no)
  41                         return ioctl;
  42         return NULL;
  43 }
  44
  45 /*
  46  * Register ioctl with number no.
  47  */
  48 int
  49 dasd_ioctl_no_register(struct module *owner, int no, dasd_ioctl_fn_t handler)
  50 {
  51         struct dasd_ioctl *new;
  52         if (dasd_find_ioctl(no))
  53                 return -EBUSY;
  54         new = kmalloc(sizeof (struct dasd_ioctl), GFP_KERNEL);
  55         if (new == NULL)
  56                 return -ENOMEM;
  57         new->owner = owner;
  58         new->no = no;
  59         new->handler = handler;
  60         list_add(&new->list, &dasd_ioctl_list);
  61         return 0;
  62 }
  63
  64 /*
  65  * Deregister ioctl with number no.
  66  */
  67 int
  68 dasd_ioctl_no_unregister(struct module *owner, int no, dasd_ioctl_fn_t handler)
  69 {
  70         struct dasd_ioctl *old = dasd_find_ioctl(no);
  71         if (old == NULL)
  72                 return -ENOENT;
  73         if (old->no != no || old->handler != handler || owner != old->owner)
  74                 return -EINVAL;
  75         list_del(&old->list);
  76         kfree(old);
  77         return 0;
  78 }
  79
  80 static int
  81 dasd_ioctl_api_version(void __user *argp)
  82 {
  83         int ver = DASD_API_VERSION;
  84         return put_user(ver, (int *)argp);
  85 }
  86
  87 /*
  88  * Enable device.
  89  * used by dasdfmt after BIODASDDISABLE to retrigger blocksize detection
  90  */
  91 static int
  92 dasd_ioctl_enable(struct block_device *bdev)
  93 {
  94         struct dasd_device *device = bdev->bd_disk->private_data;
  95
  96         if (!capable(CAP_SYS_ADMIN))
  97                 return -EACCES;
  98
  99         dasd_enable_device(device);
 100         /* Formatting the dasd device can change the capacity. */
 101         mutex_lock(&bdev->bd_mutex);
 102         i_size_write(bdev->bd_inode, (loff_t)get_capacity(device->gdp) << 9);
 103         mutex_unlock(&bdev->bd_mutex);
 104         return 0;
 105 }
 106
 107 /*
 108  * Disable device.
 109  * Used by dasdfmt. Disable I/O operations but allow ioctls.
 110  */
 111 static int
 112 dasd_ioctl_disable(struct block_device *bdev)
 113 {
 114         struct dasd_device *device = bdev->bd_disk->private_data;
 115
 116         if (!capable(CAP_SYS_ADMIN))
 117                 return -EACCES;
 118
 119         /*
 120          * Man this is sick. We don't do a real disable but only downgrade
 121          * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
 122          * BIODASDDISABLE to disable accesses to the device via the block
 123          * device layer but it still wants to do i/o on the device by
 124          * using the BIODASDFMT ioctl. Therefore the correct state for the
 125          * device is DASD_STATE_BASIC that allows to do basic i/o.
 126          */
 127         dasd_set_target_state(device, DASD_STATE_BASIC);
 128         /*
 129          * Set i_size to zero, since read, write, etc. check against this
 130          * value.
 131          */
 132         mutex_lock(&bdev->bd_mutex);
 133         i_size_write(bdev->bd_inode, 0);
 134         mutex_unlock(&bdev->bd_mutex);
 135         return 0;
 136 }
 137
 138 /*
 139  * Quiesce device.
 140  */
 141 static int
 142 dasd_ioctl_quiesce(struct dasd_device *device)
 143 {
 144         unsigned long flags;
 145
 146         if (!capable (CAP_SYS_ADMIN))
 147                 return -EACCES;
 148
 149         DEV_MESSAGE (KERN_DEBUG, device, "%s",
 150                      "Quiesce IO on device");
 151         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 152         device->stopped |= DASD_STOPPED_QUIESCE;
 153         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 154         return 0;
 155 }
 156
 157
 158 /*
 159  * Quiesce device.
 160  */
 161 static int
 162 dasd_ioctl_resume(struct dasd_device *device)
 163 {
 164         unsigned long flags;
 165
 166         if (!capable (CAP_SYS_ADMIN))
 167                 return -EACCES;
 168
 169         DEV_MESSAGE (KERN_DEBUG, device, "%s",
 170                      "resume IO on device");
 171
 172         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 173         device->stopped &= ~DASD_STOPPED_QUIESCE;
 174         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 175
 176         dasd_schedule_bh (device);
 177         return 0;
 178 }
 179
 180 /*
 181  * performs formatting of _device_ according to _fdata_
 182  * Note: The discipline's format_function is assumed to deliver formatting
 183  * commands to format a single unit of the device. In terms of the ECKD
 184  * devices this means CCWs are generated to format a single track.
 185  */
 186 static int
 187 dasd_format(struct dasd_device * device, struct format_data_t * fdata)
 188 {
 189         struct dasd_ccw_req *cqr;
 190         int rc;
 191
 192         if (device->discipline->format_device == NULL)
 193                 return -EPERM;
 194
 195         if (device->state != DASD_STATE_BASIC) {
 196                 DEV_MESSAGE(KERN_WARNING, device, "%s",
 197                             "dasd_format: device is not disabled! ");
 198                 return -EBUSY;
 199         }
 200
 201         DBF_DEV_EVENT(DBF_NOTICE, device,
 202                       "formatting units %d to %d (%d B blocks) flags %d",
 203                       fdata->start_unit,
 204                       fdata->stop_unit, fdata->blksize, fdata->intensity);
 205
 206         /* Since dasdfmt keeps the device open after it was disabled,
 207          * there still exists an inode for this device.
 208          * We must update i_blkbits, otherwise we might get errors when
 209          * enabling the device later.
 210          */
 211         if (fdata->start_unit == 0) {
 212                 struct block_device *bdev = bdget_disk(device->gdp, 0);
 213                 bdev->bd_inode->i_blkbits = blksize_bits(fdata->blksize);
 214                 bdput(bdev);
 215         }
 216
 217         while (fdata->start_unit <= fdata->stop_unit) {
 218                 cqr = device->discipline->format_device(device, fdata);
 219                 if (IS_ERR(cqr))
 220                         return PTR_ERR(cqr);
 221                 rc = dasd_sleep_on_interruptible(cqr);
 222                 dasd_sfree_request(cqr, cqr->device);
 223                 if (rc) {
 224                         if (rc != -ERESTARTSYS)
 225                                 DEV_MESSAGE(KERN_ERR, device,
 226                                             " Formatting of unit %d failed "
 227                                             "with rc = %d",
 228                                             fdata->start_unit, rc);
 229                         return rc;
 230                 }
 231                 fdata->start_unit++;
 232         }
 233         return 0;
 234 }
 235
 236 /*
 237  * Format device.
 238  */
 239 static int
 240 dasd_ioctl_format(struct block_device *bdev, void __user *argp)
 241 {
 242         struct dasd_device *device = bdev->bd_disk->private_data;
 243         struct format_data_t fdata;
 244
 245         if (!capable(CAP_SYS_ADMIN))
 246                 return -EACCES;
 247         if (!argp)
 248                 return -EINVAL;
 249
 250         if (device->features & DASD_FEATURE_READONLY)
 251                 return -EROFS;
 252         if (copy_from_user(&fdata, argp, sizeof(struct format_data_t)))
 253                 return -EFAULT;
 254         if (bdev != bdev->bd_contains) {
 255                 DEV_MESSAGE(KERN_WARNING, device, "%s",
 256                             "Cannot low-level format a partition");
 257                 return -EINVAL;
 258         }
 259         return dasd_format(device, &fdata);
 260 }
 261
 262 #ifdef CONFIG_DASD_PROFILE
 263 /*
 264  * Reset device profile information
 265  */
 266 static int
 267 dasd_ioctl_reset_profile(struct dasd_device *device)
 268 {
 269         memset(&device->profile, 0, sizeof (struct dasd_profile_info_t));
 270         return 0;
 271 }
 272
 273 /*
 274  * Return device profile information
 275  */
 276 static int
 277 dasd_ioctl_read_profile(struct dasd_device *device, void __user *argp)
 278 {
 279         if (dasd_profile_level == DASD_PROFILE_OFF)
 280                 return -EIO;
 281         if (copy_to_user(argp, &device->profile,
 282                          sizeof (struct dasd_profile_info_t)))
 283                 return -EFAULT;
 284         return 0;
 285 }
 286 #else
 287 static int
 288 dasd_ioctl_reset_profile(struct dasd_device *device)
 289 {
 290         return -ENOSYS;
 291 }
 292
 293 static int
 294 dasd_ioctl_read_profile(struct dasd_device *device, void __user *argp)
 295 {
 296         return -ENOSYS;
 297 }
 298 #endif
 299
 300 /*
 301  * Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
 302  */
 303 static int
 304 dasd_ioctl_information(struct dasd_device *device,
 305                 unsigned int cmd, void __user *argp)
 306 {
 307         struct dasd_information2_t *dasd_info;
 308         unsigned long flags;
 309         int rc;
 310         struct ccw_device *cdev;
 311
 312         if (!device->discipline->fill_info)
 313                 return -EINVAL;
 314
 315         dasd_info = kmalloc(sizeof(struct dasd_information2_t), GFP_KERNEL);
 316         if (dasd_info == NULL)
 317                 return -ENOMEM;
 318
 319         rc = device->discipline->fill_info(device, dasd_info);
 320         if (rc) {
 321                 kfree(dasd_info);
 322                 return rc;
 323         }
 324
 325         cdev = device->cdev;
 326
 327         dasd_info->devno = _ccw_device_get_device_number(device->cdev);
 328         dasd_info->schid = _ccw_device_get_subchannel_number(device->cdev);
 329         dasd_info->cu_type = cdev->id.cu_type;
 330         dasd_info->cu_model = cdev->id.cu_model;
 331         dasd_info->dev_type = cdev->id.dev_type;
 332         dasd_info->dev_model = cdev->id.dev_model;
 333         dasd_info->status = device->state;
 334         /*
 335          * The open_count is increased for every opener, that includes
 336          * the blkdev_get in dasd_scan_partitions.
 337          * This must be hidden from user-space.
 338          */
 339         dasd_info->open_count = atomic_read(&device->open_count);
 340         if (!device->bdev)
 341                 dasd_info->open_count++;
 342
 343         /*
 344          * check if device is really formatted
 345          * LDL / CDL was returned by 'fill_info'
 346          */
 347         if ((device->state < DASD_STATE_READY) ||
 348             (dasd_check_blocksize(device->bp_block)))
 349                 dasd_info->format = DASD_FORMAT_NONE;
 350
 351         dasd_info->features |=
 352                 ((device->features & DASD_FEATURE_READONLY) != 0);
 353
 354         if (device->discipline)
 355                 memcpy(dasd_info->type, device->discipline->name, 4);
 356         else
 357                 memcpy(dasd_info->type, "none", 4);
 358         dasd_info->req_queue_len = 0;
 359         dasd_info->chanq_len = 0;
 360         if (device->request_queue->request_fn) {
 361                 struct list_head *l;
 362 #ifdef DASD_EXTENDED_PROFILING
 363                 {
 364                         struct list_head *l;
 365                         spin_lock_irqsave(&device->lock, flags);
 366                         list_for_each(l, &device->request_queue->queue_head)
 367                                 dasd_info->req_queue_len++;
 368                         spin_unlock_irqrestore(&device->lock, flags);
 369                 }
 370 #endif                          /* DASD_EXTENDED_PROFILING */
 371                 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 372                 list_for_each(l, &device->ccw_queue)
 373                         dasd_info->chanq_len++;
 374                 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev),
 375                                        flags);
 376         }
 377
 378         rc = 0;
 379         if (copy_to_user(argp, dasd_info,
 380                          ((cmd == (unsigned int) BIODASDINFO2) ?
 381                           sizeof (struct dasd_information2_t) :
 382                           sizeof (struct dasd_information_t))))
 383                 rc = -EFAULT;
 384         kfree(dasd_info);
 385         return rc;
 386 }
 387
 388 /*
 389  * Set read only
 390  */
 391 static int
 392 dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
 393 {
 394         struct dasd_device *device =  bdev->bd_disk->private_data;
 395         int intval;
 396
 397         if (!capable(CAP_SYS_ADMIN))
 398                 return -EACCES;
 399         if (bdev != bdev->bd_contains)
 400                 // ro setting is not allowed for partitions
 401                 return -EINVAL;
 402         if (get_user(intval, (int *)argp))
 403                 return -EFAULT;
 404
 405         set_disk_ro(bdev->bd_disk, intval);
 406         return dasd_set_feature(device->cdev, DASD_FEATURE_READONLY, intval);
 407 }
 408
 409 int
 410 dasd_ioctl(struct inode *inode, struct file *file,
 411            unsigned int cmd, unsigned long arg)
 412 {
 413         struct block_device *bdev = inode->i_bdev;
 414         struct dasd_device *device = bdev->bd_disk->private_data;
 415         void __user *argp = (void __user *)arg;
 416         struct dasd_ioctl *ioctl;
 417         int rc;
 418
 419         if (!device)
 420                 return -ENODEV;
 421
 422         if ((_IOC_DIR(cmd) != _IOC_NONE) && !arg) {
 423                 PRINT_DEBUG("empty data ptr");
 424                 return -EINVAL;
 425         }
 426
 427         switch (cmd) {
 428         case BIODASDDISABLE:
 429                 return dasd_ioctl_disable(bdev);
 430         case BIODASDENABLE:
 431                 return dasd_ioctl_enable(bdev);
 432         case BIODASDQUIESCE:
 433                 return dasd_ioctl_quiesce(device);
 434         case BIODASDRESUME:
 435                 return dasd_ioctl_resume(device);
 436         case BIODASDFMT:
 437                 return dasd_ioctl_format(bdev, argp);
 438         case BIODASDINFO:
 439                 return dasd_ioctl_information(device, cmd, argp);
 440         case BIODASDINFO2:
 441                 return dasd_ioctl_information(device, cmd, argp);
 442         case BIODASDPRRD:
 443                 return dasd_ioctl_read_profile(device, argp);
 444         case BIODASDPRRST:
 445                 return dasd_ioctl_reset_profile(device);
 446         case BLKROSET:
 447                 return dasd_ioctl_set_ro(bdev, argp);
 448         case DASDAPIVER:
 449                 return dasd_ioctl_api_version(argp);
 450         default:
 451                 /* resort to the deprecated dynamic ioctl list */
 452                 list_for_each_entry(ioctl, &dasd_ioctl_list, list) {
 453                         if (ioctl->no == cmd) {
 454                                 /* Found a matching ioctl. Call it. */
 455                                 if (!try_module_get(ioctl->owner))
 456                                         continue;
 457                                 rc = ioctl->handler(bdev, cmd, arg);
 458                                 module_put(ioctl->owner);
 459                                 return rc;
 460                         }
 461                 }
 462                 return -EINVAL;
 463         }
 464 }
 465
 466 long
 467 dasd_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 468 {
 469         int rval;
 470
 471         lock_kernel();
 472         rval = dasd_ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
 473         unlock_kernel();
 474
 475         return (rval == -EINVAL) ? -ENOIOCTLCMD : rval;
 476 }
 477
 478 EXPORT_SYMBOL(dasd_ioctl_no_register);
 479 EXPORT_SYMBOL(dasd_ioctl_no_unregister);