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