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  * $Revision: 1.45 $
  11  *
  12  * i/o controls for the dasd driver.
  13  */
  14 #include <linux/config.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/major.h>
  17 #include <linux/fs.h>
  18 #include <linux/blkpg.h>
  19
  20 #include <asm/ccwdev.h>
  21 #include <asm/uaccess.h>
  22
  23 /* This is ugly... */
  24 #define PRINTK_HEADER "dasd_ioctl:"
  25
  26 #include "dasd_int.h"
  27
  28 /*
  29  * SECTION: ioctl functions.
  30  */
  31 static struct list_head dasd_ioctl_list = LIST_HEAD_INIT(dasd_ioctl_list);
  32
  33 /*
  34  * Find the ioctl with number no.
  35  */
  36 static struct dasd_ioctl *
  37 dasd_find_ioctl(int no)
  38 {
  39         struct dasd_ioctl *ioctl;
  40
  41         list_for_each_entry (ioctl, &dasd_ioctl_list, list)
  42                 if (ioctl->no == no)
  43                         return ioctl;
  44         return NULL;
  45 }
  46
  47 /*
  48  * Register ioctl with number no.
  49  */
  50 int
  51 dasd_ioctl_no_register(struct module *owner, int no, dasd_ioctl_fn_t handler)
  52 {
  53         struct dasd_ioctl *new;
  54         if (dasd_find_ioctl(no))
  55                 return -EBUSY;
  56         new = kmalloc(sizeof (struct dasd_ioctl), GFP_KERNEL);
  57         if (new == NULL)
  58                 return -ENOMEM;
  59         new->owner = owner;
  60         new->no = no;
  61         new->handler = handler;
  62         list_add(&new->list, &dasd_ioctl_list);
  63         return 0;
  64 }
  65
  66 /*
  67  * Deregister ioctl with number no.
  68  */
  69 int
  70 dasd_ioctl_no_unregister(struct module *owner, int no, dasd_ioctl_fn_t handler)
  71 {
  72         struct dasd_ioctl *old = dasd_find_ioctl(no);
  73         if (old == NULL)
  74                 return -ENOENT;
  75         if (old->no != no || old->handler != handler || owner != old->owner)
  76                 return -EINVAL;
  77         list_del(&old->list);
  78         kfree(old);
  79         return 0;
  80 }
  81
  82 int
  83 dasd_ioctl(struct inode *inp, struct file *filp,
  84            unsigned int no, unsigned long data)
  85 {
  86         struct block_device *bdev = inp->i_bdev;
  87         struct dasd_device *device = bdev->bd_disk->private_data;
  88         struct dasd_ioctl *ioctl;
  89         const char *dir;
  90         int rc;
  91
  92         if ((_IOC_DIR(no) != _IOC_NONE) && (data == 0)) {
  93                 PRINT_DEBUG("empty data ptr");
  94                 return -EINVAL;
  95         }
  96         dir = _IOC_DIR (no) == _IOC_NONE ? "0" :
  97                 _IOC_DIR (no) == _IOC_READ ? "r" :
  98                 _IOC_DIR (no) == _IOC_WRITE ? "w" :
  99                 _IOC_DIR (no) == (_IOC_READ | _IOC_WRITE) ? "rw" : "u";
 100         DBF_DEV_EVENT(DBF_DEBUG, device,
 101                       "ioctl 0x%08x %s'0x%x'%d(%d) with data %8lx", no,
 102                       dir, _IOC_TYPE(no), _IOC_NR(no), _IOC_SIZE(no), data);
 103         /* Search for ioctl no in the ioctl list. */
 104         list_for_each_entry(ioctl, &dasd_ioctl_list, list) {
 105                 if (ioctl->no == no) {
 106                         /* Found a matching ioctl. Call it. */
 107                         if (!try_module_get(ioctl->owner))
 108                                 continue;
 109                         rc = ioctl->handler(bdev, no, data);
 110                         module_put(ioctl->owner);
 111                         return rc;
 112                 }
 113         }
 114         /* No ioctl with number no. */
 115         DBF_DEV_EVENT(DBF_INFO, device,
 116                       "unknown ioctl 0x%08x=%s'0x%x'%d(%d) data %8lx", no,
 117                       dir, _IOC_TYPE(no), _IOC_NR(no), _IOC_SIZE(no), data);
 118         return -EINVAL;
 119 }
 120
 121 static int
 122 dasd_ioctl_api_version(struct block_device *bdev, int no, long args)
 123 {
 124         int ver = DASD_API_VERSION;
 125         return put_user(ver, (int __user *) args);
 126 }
 127
 128 /*
 129  * Enable device.
 130  * used by dasdfmt after BIODASDDISABLE to retrigger blocksize detection
 131  */
 132 static int
 133 dasd_ioctl_enable(struct block_device *bdev, int no, long args)
 134 {
 135         struct dasd_device *device;
 136
 137         if (!capable(CAP_SYS_ADMIN))
 138                 return -EACCES;
 139         device = bdev->bd_disk->private_data;
 140         if (device == NULL)
 141                 return -ENODEV;
 142         dasd_enable_device(device);
 143         /* Formatting the dasd device can change the capacity. */
 144         down(&bdev->bd_sem);
 145         i_size_write(bdev->bd_inode, (loff_t)get_capacity(device->gdp) << 9);
 146         up(&bdev->bd_sem);
 147         return 0;
 148 }
 149
 150 /*
 151  * Disable device.
 152  * Used by dasdfmt. Disable I/O operations but allow ioctls.
 153  */
 154 static int
 155 dasd_ioctl_disable(struct block_device *bdev, int no, long args)
 156 {
 157         struct dasd_device *device;
 158
 159         if (!capable(CAP_SYS_ADMIN))
 160                 return -EACCES;
 161         device = bdev->bd_disk->private_data;
 162         if (device == NULL)
 163                 return -ENODEV;
 164         /*
 165          * Man this is sick. We don't do a real disable but only downgrade
 166          * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
 167          * BIODASDDISABLE to disable accesses to the device via the block
 168          * device layer but it still wants to do i/o on the device by
 169          * using the BIODASDFMT ioctl. Therefore the correct state for the
 170          * device is DASD_STATE_BASIC that allows to do basic i/o.
 171          */
 172         dasd_set_target_state(device, DASD_STATE_BASIC);
 173         /*
 174          * Set i_size to zero, since read, write, etc. check against this
 175          * value.
 176          */
 177         down(&bdev->bd_sem);
 178         i_size_write(bdev->bd_inode, 0);
 179         up(&bdev->bd_sem);
 180         return 0;
 181 }
 182
 183 /*
 184  * Quiesce device.
 185  */
 186 static int
 187 dasd_ioctl_quiesce(struct block_device *bdev, int no, long args)
 188 {
 189         struct dasd_device *device;
 190         unsigned long flags;
 191
 192         if (!capable (CAP_SYS_ADMIN))
 193                 return -EACCES;
 194
 195         device = bdev->bd_disk->private_data;
 196         if (device == NULL)
 197                 return -ENODEV;
 198
 199         DEV_MESSAGE (KERN_DEBUG, device, "%s",
 200                      "Quiesce IO on device");
 201         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 202         device->stopped |= DASD_STOPPED_QUIESCE;
 203         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 204         return 0;
 205 }
 206
 207
 208 /*
 209  * Quiesce device.
 210  */
 211 static int
 212 dasd_ioctl_resume(struct block_device *bdev, int no, long args)
 213 {
 214         struct dasd_device *device;
 215         unsigned long flags;
 216
 217         if (!capable (CAP_SYS_ADMIN))
 218                 return -EACCES;
 219
 220         device = bdev->bd_disk->private_data;
 221         if (device == NULL)
 222                 return -ENODEV;
 223
 224         DEV_MESSAGE (KERN_DEBUG, device, "%s",
 225                      "resume IO on device");
 226
 227         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 228         device->stopped &= ~DASD_STOPPED_QUIESCE;
 229         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
 230
 231         dasd_schedule_bh (device);
 232         return 0;
 233 }
 234
 235 /*
 236  * performs formatting of _device_ according to _fdata_
 237  * Note: The discipline's format_function is assumed to deliver formatting
 238  * commands to format a single unit of the device. In terms of the ECKD
 239  * devices this means CCWs are generated to format a single track.
 240  */
 241 static int
 242 dasd_format(struct dasd_device * device, struct format_data_t * fdata)
 243 {
 244         struct dasd_ccw_req *cqr;
 245         int rc;
 246
 247         if (device->discipline->format_device == NULL)
 248                 return -EPERM;
 249
 250         if (device->state != DASD_STATE_BASIC) {
 251                 DEV_MESSAGE(KERN_WARNING, device, "%s",
 252                             "dasd_format: device is not disabled! ");
 253                 return -EBUSY;
 254         }
 255
 256         DBF_DEV_EVENT(DBF_NOTICE, device,
 257                       "formatting units %d to %d (%d B blocks) flags %d",
 258                       fdata->start_unit,
 259                       fdata->stop_unit, fdata->blksize, fdata->intensity);
 260
 261         /* Since dasdfmt keeps the device open after it was disabled,
 262          * there still exists an inode for this device.
 263          * We must update i_blkbits, otherwise we might get errors when
 264          * enabling the device later.
 265          */
 266         if (fdata->start_unit == 0) {
 267                 struct block_device *bdev = bdget_disk(device->gdp, 0);
 268                 bdev->bd_inode->i_blkbits = blksize_bits(fdata->blksize);
 269                 bdput(bdev);
 270         }
 271
 272         while (fdata->start_unit <= fdata->stop_unit) {
 273                 cqr = device->discipline->format_device(device, fdata);
 274                 if (IS_ERR(cqr))
 275                         return PTR_ERR(cqr);
 276                 rc = dasd_sleep_on_interruptible(cqr);
 277                 dasd_sfree_request(cqr, cqr->device);
 278                 if (rc) {
 279                         if (rc != -ERESTARTSYS)
 280                                 DEV_MESSAGE(KERN_ERR, device,
 281                                             " Formatting of unit %d failed "
 282                                             "with rc = %d",
 283                                             fdata->start_unit, rc);
 284                         return rc;
 285                 }
 286                 fdata->start_unit++;
 287         }
 288         return 0;
 289 }
 290
 291 /*
 292  * Format device.
 293  */
 294 static int
 295 dasd_ioctl_format(struct block_device *bdev, int no, long args)
 296 {
 297         struct dasd_device *device;
 298         struct format_data_t fdata;
 299         int feature_ro;
 300
 301         if (!capable(CAP_SYS_ADMIN))
 302                 return -EACCES;
 303         if (!args)
 304                 return -EINVAL;
 305         /* fdata == NULL is no longer a valid arg to dasd_format ! */
 306         device = bdev->bd_disk->private_data;
 307
 308         if (device == NULL)
 309                 return -ENODEV;
 310
 311         feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
 312         if (feature_ro < 0)
 313                 return feature_ro;
 314         if (feature_ro)
 315                 return -EROFS;
 316         if (copy_from_user(&fdata, (void __user *) args,
 317                            sizeof (struct format_data_t)))
 318                 return -EFAULT;
 319         if (bdev != bdev->bd_contains) {
 320                 DEV_MESSAGE(KERN_WARNING, device, "%s",
 321                             "Cannot low-level format a partition");
 322                 return -EINVAL;
 323         }
 324         return dasd_format(device, &fdata);
 325 }
 326
 327 #ifdef CONFIG_DASD_PROFILE
 328 /*
 329  * Reset device profile information
 330  */
 331 static int
 332 dasd_ioctl_reset_profile(struct block_device *bdev, int no, long args)
 333 {
 334         struct dasd_device *device;
 335
 336         if (!capable(CAP_SYS_ADMIN))
 337                 return -EACCES;
 338
 339         device = bdev->bd_disk->private_data;
 340         if (device == NULL)
 341                 return -ENODEV;
 342
 343         memset(&device->profile, 0, sizeof (struct dasd_profile_info_t));
 344         return 0;
 345 }
 346
 347 /*
 348  * Return device profile information
 349  */
 350 static int
 351 dasd_ioctl_read_profile(struct block_device *bdev, int no, long args)
 352 {
 353         struct dasd_device *device;
 354
 355         device = bdev->bd_disk->private_data;
 356         if (device == NULL)
 357                 return -ENODEV;
 358
 359         if (copy_to_user((long __user *) args, (long *) &device->profile,
 360                          sizeof (struct dasd_profile_info_t)))
 361                 return -EFAULT;
 362         return 0;
 363 }
 364 #else
 365 static int
 366 dasd_ioctl_reset_profile(struct block_device *bdev, int no, long args)
 367 {
 368         return -ENOSYS;
 369 }
 370
 371 static int
 372 dasd_ioctl_read_profile(struct block_device *bdev, int no, long args)
 373 {
 374         return -ENOSYS;
 375 }
 376 #endif
 377
 378 /*
 379  * Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
 380  */
 381 static int
 382 dasd_ioctl_information(struct block_device *bdev, int no, long args)
 383 {
 384         struct dasd_device *device;
 385         struct dasd_information2_t *dasd_info;
 386         unsigned long flags;
 387         int rc, feature_ro;
 388         struct ccw_device *cdev;
 389
 390         device = bdev->bd_disk->private_data;
 391         if (device == NULL)
 392                 return -ENODEV;
 393
 394         if (!device->discipline->fill_info)
 395                 return -EINVAL;
 396
 397         feature_ro = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
 398         if (feature_ro < 0)
 399                 return feature_ro;
 400
 401         dasd_info = kmalloc(sizeof(struct dasd_information2_t), GFP_KERNEL);
 402         if (dasd_info == NULL)
 403                 return -ENOMEM;
 404
 405         rc = device->discipline->fill_info(device, dasd_info);
 406         if (rc) {
 407                 kfree(dasd_info);
 408                 return rc;
 409         }
 410
 411         cdev = device->cdev;
 412
 413         dasd_info->devno = _ccw_device_get_device_number(device->cdev);
 414         dasd_info->schid = _ccw_device_get_subchannel_number(device->cdev);
 415         dasd_info->cu_type = cdev->id.cu_type;
 416         dasd_info->cu_model = cdev->id.cu_model;
 417         dasd_info->dev_type = cdev->id.dev_type;
 418         dasd_info->dev_model = cdev->id.dev_model;
 419         dasd_info->open_count = atomic_read(&device->open_count);
 420         dasd_info->status = device->state;
 421
 422         /*
 423          * check if device is really formatted
 424          * LDL / CDL was returned by 'fill_info'
 425          */
 426         if ((device->state < DASD_STATE_READY) ||
 427             (dasd_check_blocksize(device->bp_block)))
 428                 dasd_info->format = DASD_FORMAT_NONE;
 429
 430         dasd_info->features |= feature_ro;
 431
 432         if (device->discipline)
 433                 memcpy(dasd_info->type, device->discipline->name, 4);
 434         else
 435                 memcpy(dasd_info->type, "none", 4);
 436         dasd_info->req_queue_len = 0;
 437         dasd_info->chanq_len = 0;
 438         if (device->request_queue->request_fn) {
 439                 struct list_head *l;
 440 #ifdef DASD_EXTENDED_PROFILING
 441                 {
 442                         struct list_head *l;
 443                         spin_lock_irqsave(&device->lock, flags);
 444                         list_for_each(l, &device->request_queue->queue_head)
 445                                 dasd_info->req_queue_len++;
 446                         spin_unlock_irqrestore(&device->lock, flags);
 447                 }
 448 #endif                          /* DASD_EXTENDED_PROFILING */
 449                 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
 450                 list_for_each(l, &device->ccw_queue)
 451                         dasd_info->chanq_len++;
 452                 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev),
 453                                        flags);
 454         }
 455
 456         rc = 0;
 457         if (copy_to_user((long __user *) args, (long *) dasd_info,
 458                          ((no == (unsigned int) BIODASDINFO2) ?
 459                           sizeof (struct dasd_information2_t) :
 460                           sizeof (struct dasd_information_t))))
 461                 rc = -EFAULT;
 462         kfree(dasd_info);
 463         return rc;
 464 }
 465
 466 /*
 467  * Set read only
 468  */
 469 static int
 470 dasd_ioctl_set_ro(struct block_device *bdev, int no, long args)
 471 {
 472         struct dasd_device *device;
 473         int intval, rc;
 474
 475         if (!capable(CAP_SYS_ADMIN))
 476                 return -EACCES;
 477         if (bdev != bdev->bd_contains)
 478                 // ro setting is not allowed for partitions
 479                 return -EINVAL;
 480         if (get_user(intval, (int __user *) args))
 481                 return -EFAULT;
 482         device =  bdev->bd_disk->private_data;
 483         if (device == NULL)
 484                 return -ENODEV;
 485
 486         set_disk_ro(bdev->bd_disk, intval);
 487         rc = dasd_set_feature(device->cdev, DASD_FEATURE_READONLY, intval);
 488
 489         return rc;
 490 }
 491
 492 /*
 493  * Return disk geometry.
 494  */
 495 static int
 496 dasd_ioctl_getgeo(struct block_device *bdev, int no, long args)
 497 {
 498         struct hd_geometry geo = { 0, };
 499         struct dasd_device *device;
 500
 501         device =  bdev->bd_disk->private_data;
 502         if (device == NULL)
 503                 return -ENODEV;
 504
 505         if (device == NULL || device->discipline == NULL ||
 506             device->discipline->fill_geometry == NULL)
 507                 return -EINVAL;
 508
 509         geo = (struct hd_geometry) {};
 510         device->discipline->fill_geometry(device, &geo);
 511         geo.start = get_start_sect(bdev) >> device->s2b_shift;
 512         if (copy_to_user((struct hd_geometry __user *) args, &geo,
 513                          sizeof (struct hd_geometry)))
 514                 return -EFAULT;
 515
 516         return 0;
 517 }
 518
 519 /*
 520  * List of static ioctls.
 521  */
 522 static struct { int no; dasd_ioctl_fn_t fn; } dasd_ioctls[] =
 523 {
 524         { BIODASDDISABLE, dasd_ioctl_disable },
 525         { BIODASDENABLE, dasd_ioctl_enable },
 526         { BIODASDQUIESCE, dasd_ioctl_quiesce },
 527         { BIODASDRESUME, dasd_ioctl_resume },
 528         { BIODASDFMT, dasd_ioctl_format },
 529         { BIODASDINFO, dasd_ioctl_information },
 530         { BIODASDINFO2, dasd_ioctl_information },
 531         { BIODASDPRRD, dasd_ioctl_read_profile },
 532         { BIODASDPRRST, dasd_ioctl_reset_profile },
 533         { BLKROSET, dasd_ioctl_set_ro },
 534         { DASDAPIVER, dasd_ioctl_api_version },
 535         { HDIO_GETGEO, dasd_ioctl_getgeo },
 536         { -1, NULL }
 537 };
 538
 539 int
 540 dasd_ioctl_init(void)
 541 {
 542         int i;
 543
 544         for (i = 0; dasd_ioctls[i].no != -1; i++)
 545                 dasd_ioctl_no_register(NULL, dasd_ioctls[i].no,
 546                                        dasd_ioctls[i].fn);
 547         return 0;
 548
 549 }
 550
 551 void
 552 dasd_ioctl_exit(void)
 553 {
 554         int i;
 555
 556         for (i = 0; dasd_ioctls[i].no != -1; i++)
 557                 dasd_ioctl_no_unregister(NULL, dasd_ioctls[i].no,
 558                                          dasd_ioctls[i].fn);
 559
 560 }
 561
 562 EXPORT_SYMBOL(dasd_ioctl_no_register);
 563 EXPORT_SYMBOL(dasd_ioctl_no_unregister);