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