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