xref: /openbmc/linux/drivers/s390/block/dasd_ioctl.c (revision c4c3c32d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
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  * Copyright IBM Corp. 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/compat.h>
17 #include <linux/major.h>
18 #include <linux/fs.h>
19 #include <linux/blkpg.h>
20 #include <linux/slab.h>
21 #include <asm/ccwdev.h>
22 #include <asm/schid.h>
23 #include <asm/cmb.h>
24 #include <linux/uaccess.h>
25 #include <linux/dasd_mod.h>
26 
27 /* This is ugly... */
28 #define PRINTK_HEADER "dasd_ioctl:"
29 
30 #include "dasd_int.h"
31 
32 
33 static int
34 dasd_ioctl_api_version(void __user *argp)
35 {
36 	int ver = DASD_API_VERSION;
37 	return put_user(ver, (int __user *)argp);
38 }
39 
40 /*
41  * Enable device.
42  * used by dasdfmt after BIODASDDISABLE to retrigger blocksize detection
43  */
44 static int
45 dasd_ioctl_enable(struct block_device *bdev)
46 {
47 	struct dasd_device *base;
48 
49 	if (!capable(CAP_SYS_ADMIN))
50 		return -EACCES;
51 
52 	base = dasd_device_from_gendisk(bdev->bd_disk);
53 	if (!base)
54 		return -ENODEV;
55 
56 	dasd_enable_device(base);
57 	dasd_put_device(base);
58 	return 0;
59 }
60 
61 /*
62  * Disable device.
63  * Used by dasdfmt. Disable I/O operations but allow ioctls.
64  */
65 static int
66 dasd_ioctl_disable(struct block_device *bdev)
67 {
68 	struct dasd_device *base;
69 
70 	if (!capable(CAP_SYS_ADMIN))
71 		return -EACCES;
72 
73 	base = dasd_device_from_gendisk(bdev->bd_disk);
74 	if (!base)
75 		return -ENODEV;
76 	/*
77 	 * Man this is sick. We don't do a real disable but only downgrade
78 	 * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
79 	 * BIODASDDISABLE to disable accesses to the device via the block
80 	 * device layer but it still wants to do i/o on the device by
81 	 * using the BIODASDFMT ioctl. Therefore the correct state for the
82 	 * device is DASD_STATE_BASIC that allows to do basic i/o.
83 	 */
84 	dasd_set_target_state(base, DASD_STATE_BASIC);
85 	/*
86 	 * Set i_size to zero, since read, write, etc. check against this
87 	 * value.
88 	 */
89 	set_capacity(bdev->bd_disk, 0);
90 	dasd_put_device(base);
91 	return 0;
92 }
93 
94 /*
95  * Quiesce device.
96  */
97 static int dasd_ioctl_quiesce(struct dasd_block *block)
98 {
99 	unsigned long flags;
100 	struct dasd_device *base;
101 
102 	base = block->base;
103 	if (!capable (CAP_SYS_ADMIN))
104 		return -EACCES;
105 
106 	pr_info("%s: The DASD has been put in the quiesce "
107 		"state\n", dev_name(&base->cdev->dev));
108 	spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
109 	dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
110 	spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
111 	return 0;
112 }
113 
114 
115 /*
116  * Resume device.
117  */
118 static int dasd_ioctl_resume(struct dasd_block *block)
119 {
120 	unsigned long flags;
121 	struct dasd_device *base;
122 
123 	base = block->base;
124 	if (!capable (CAP_SYS_ADMIN))
125 		return -EACCES;
126 
127 	pr_info("%s: I/O operations have been resumed "
128 		"on the DASD\n", dev_name(&base->cdev->dev));
129 	spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
130 	dasd_device_remove_stop_bits(base, DASD_STOPPED_QUIESCE);
131 	spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
132 
133 	dasd_schedule_block_bh(block);
134 	dasd_schedule_device_bh(base);
135 	return 0;
136 }
137 
138 /*
139  * Abort all failfast I/O on a device.
140  */
141 static int dasd_ioctl_abortio(struct dasd_block *block)
142 {
143 	unsigned long flags;
144 	struct dasd_device *base;
145 	struct dasd_ccw_req *cqr, *n;
146 
147 	base = block->base;
148 	if (!capable(CAP_SYS_ADMIN))
149 		return -EACCES;
150 
151 	if (test_and_set_bit(DASD_FLAG_ABORTALL, &base->flags))
152 		return 0;
153 	DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag set");
154 
155 	spin_lock_irqsave(&block->request_queue_lock, flags);
156 	spin_lock(&block->queue_lock);
157 	list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
158 		if (test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
159 		    cqr->callback_data &&
160 		    cqr->callback_data != DASD_SLEEPON_START_TAG &&
161 		    cqr->callback_data != DASD_SLEEPON_END_TAG) {
162 			spin_unlock(&block->queue_lock);
163 			blk_abort_request(cqr->callback_data);
164 			spin_lock(&block->queue_lock);
165 		}
166 	}
167 	spin_unlock(&block->queue_lock);
168 	spin_unlock_irqrestore(&block->request_queue_lock, flags);
169 
170 	dasd_schedule_block_bh(block);
171 	return 0;
172 }
173 
174 /*
175  * Allow I/O on a device
176  */
177 static int dasd_ioctl_allowio(struct dasd_block *block)
178 {
179 	struct dasd_device *base;
180 
181 	base = block->base;
182 	if (!capable(CAP_SYS_ADMIN))
183 		return -EACCES;
184 
185 	if (test_and_clear_bit(DASD_FLAG_ABORTALL, &base->flags))
186 		DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag unset");
187 
188 	return 0;
189 }
190 
191 /*
192  * performs formatting of _device_ according to _fdata_
193  * Note: The discipline's format_function is assumed to deliver formatting
194  * commands to format multiple units of the device. In terms of the ECKD
195  * devices this means CCWs are generated to format multiple tracks.
196  */
197 static int
198 dasd_format(struct dasd_block *block, struct format_data_t *fdata)
199 {
200 	struct dasd_device *base;
201 	int rc;
202 
203 	base = block->base;
204 	if (base->discipline->format_device == NULL)
205 		return -EPERM;
206 
207 	if (base->state != DASD_STATE_BASIC) {
208 		pr_warn("%s: The DASD cannot be formatted while it is enabled\n",
209 			dev_name(&base->cdev->dev));
210 		return -EBUSY;
211 	}
212 
213 	DBF_DEV_EVENT(DBF_NOTICE, base,
214 		      "formatting units %u to %u (%u B blocks) flags %u",
215 		      fdata->start_unit,
216 		      fdata->stop_unit, fdata->blksize, fdata->intensity);
217 
218 	/* Since dasdfmt keeps the device open after it was disabled,
219 	 * there still exists an inode for this device.
220 	 * We must update i_blkbits, otherwise we might get errors when
221 	 * enabling the device later.
222 	 */
223 	if (fdata->start_unit == 0) {
224 		block->gdp->part0->bd_inode->i_blkbits =
225 			blksize_bits(fdata->blksize);
226 	}
227 
228 	rc = base->discipline->format_device(base, fdata, 1);
229 	if (rc == -EAGAIN)
230 		rc = base->discipline->format_device(base, fdata, 0);
231 
232 	return rc;
233 }
234 
235 static int dasd_check_format(struct dasd_block *block,
236 			     struct format_check_t *cdata)
237 {
238 	struct dasd_device *base;
239 	int rc;
240 
241 	base = block->base;
242 	if (!base->discipline->check_device_format)
243 		return -ENOTTY;
244 
245 	rc = base->discipline->check_device_format(base, cdata, 1);
246 	if (rc == -EAGAIN)
247 		rc = base->discipline->check_device_format(base, cdata, 0);
248 
249 	return rc;
250 }
251 
252 /*
253  * Format device.
254  */
255 static int
256 dasd_ioctl_format(struct block_device *bdev, void __user *argp)
257 {
258 	struct dasd_device *base;
259 	struct format_data_t fdata;
260 	int rc;
261 
262 	if (!capable(CAP_SYS_ADMIN))
263 		return -EACCES;
264 	if (!argp)
265 		return -EINVAL;
266 	base = dasd_device_from_gendisk(bdev->bd_disk);
267 	if (!base)
268 		return -ENODEV;
269 	if (base->features & DASD_FEATURE_READONLY ||
270 	    test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
271 		dasd_put_device(base);
272 		return -EROFS;
273 	}
274 	if (copy_from_user(&fdata, argp, sizeof(struct format_data_t))) {
275 		dasd_put_device(base);
276 		return -EFAULT;
277 	}
278 	if (bdev_is_partition(bdev)) {
279 		pr_warn("%s: The specified DASD is a partition and cannot be formatted\n",
280 			dev_name(&base->cdev->dev));
281 		dasd_put_device(base);
282 		return -EINVAL;
283 	}
284 	rc = dasd_format(base->block, &fdata);
285 	dasd_put_device(base);
286 
287 	return rc;
288 }
289 
290 /*
291  * Check device format
292  */
293 static int dasd_ioctl_check_format(struct block_device *bdev, void __user *argp)
294 {
295 	struct format_check_t cdata;
296 	struct dasd_device *base;
297 	int rc = 0;
298 
299 	if (!argp)
300 		return -EINVAL;
301 
302 	base = dasd_device_from_gendisk(bdev->bd_disk);
303 	if (!base)
304 		return -ENODEV;
305 	if (bdev_is_partition(bdev)) {
306 		pr_warn("%s: The specified DASD is a partition and cannot be checked\n",
307 			dev_name(&base->cdev->dev));
308 		rc = -EINVAL;
309 		goto out_err;
310 	}
311 
312 	if (copy_from_user(&cdata, argp, sizeof(cdata))) {
313 		rc = -EFAULT;
314 		goto out_err;
315 	}
316 
317 	rc = dasd_check_format(base->block, &cdata);
318 	if (rc)
319 		goto out_err;
320 
321 	if (copy_to_user(argp, &cdata, sizeof(cdata)))
322 		rc = -EFAULT;
323 
324 out_err:
325 	dasd_put_device(base);
326 
327 	return rc;
328 }
329 
330 static int dasd_release_space(struct dasd_device *device,
331 			      struct format_data_t *rdata)
332 {
333 	if (!device->discipline->is_ese && !device->discipline->is_ese(device))
334 		return -ENOTSUPP;
335 	if (!device->discipline->release_space)
336 		return -ENOTSUPP;
337 
338 	return device->discipline->release_space(device, rdata);
339 }
340 
341 /*
342  * Release allocated space
343  */
344 static int dasd_ioctl_release_space(struct block_device *bdev, void __user *argp)
345 {
346 	struct format_data_t rdata;
347 	struct dasd_device *base;
348 	int rc = 0;
349 
350 	if (!capable(CAP_SYS_ADMIN))
351 		return -EACCES;
352 	if (!argp)
353 		return -EINVAL;
354 
355 	base = dasd_device_from_gendisk(bdev->bd_disk);
356 	if (!base)
357 		return -ENODEV;
358 	if (base->features & DASD_FEATURE_READONLY ||
359 	    test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
360 		rc = -EROFS;
361 		goto out_err;
362 	}
363 	if (bdev_is_partition(bdev)) {
364 		pr_warn("%s: The specified DASD is a partition and tracks cannot be released\n",
365 			dev_name(&base->cdev->dev));
366 		rc = -EINVAL;
367 		goto out_err;
368 	}
369 
370 	if (copy_from_user(&rdata, argp, sizeof(rdata))) {
371 		rc = -EFAULT;
372 		goto out_err;
373 	}
374 
375 	rc = dasd_release_space(base, &rdata);
376 
377 out_err:
378 	dasd_put_device(base);
379 
380 	return rc;
381 }
382 
383 /*
384  * Swap driver iternal copy relation.
385  */
386 static int
387 dasd_ioctl_copy_pair_swap(struct block_device *bdev, void __user *argp)
388 {
389 	struct dasd_copypair_swap_data_t data;
390 	struct dasd_device *device;
391 	int rc;
392 
393 	if (!capable(CAP_SYS_ADMIN))
394 		return -EACCES;
395 
396 	device = dasd_device_from_gendisk(bdev->bd_disk);
397 	if (!device)
398 		return -ENODEV;
399 
400 	if (copy_from_user(&data, argp, sizeof(struct dasd_copypair_swap_data_t))) {
401 		dasd_put_device(device);
402 		return -EFAULT;
403 	}
404 	if (memchr_inv(data.reserved, 0, sizeof(data.reserved))) {
405 		pr_warn("%s: Invalid swap data specified\n",
406 			dev_name(&device->cdev->dev));
407 		dasd_put_device(device);
408 		return DASD_COPYPAIRSWAP_INVALID;
409 	}
410 	if (bdev_is_partition(bdev)) {
411 		pr_warn("%s: The specified DASD is a partition and cannot be swapped\n",
412 			dev_name(&device->cdev->dev));
413 		dasd_put_device(device);
414 		return DASD_COPYPAIRSWAP_INVALID;
415 	}
416 	if (!device->copy) {
417 		pr_warn("%s: The specified DASD has no copy pair set up\n",
418 			dev_name(&device->cdev->dev));
419 		dasd_put_device(device);
420 		return -ENODEV;
421 	}
422 	if (!device->discipline->copy_pair_swap) {
423 		dasd_put_device(device);
424 		return -EOPNOTSUPP;
425 	}
426 	rc = device->discipline->copy_pair_swap(device, data.primary,
427 						data.secondary);
428 	dasd_put_device(device);
429 
430 	return rc;
431 }
432 
433 #ifdef CONFIG_DASD_PROFILE
434 /*
435  * Reset device profile information
436  */
437 static int dasd_ioctl_reset_profile(struct dasd_block *block)
438 {
439 	dasd_profile_reset(&block->profile);
440 	return 0;
441 }
442 
443 /*
444  * Return device profile information
445  */
446 static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
447 {
448 	struct dasd_profile_info_t *data;
449 	int rc = 0;
450 
451 	data = kmalloc(sizeof(*data), GFP_KERNEL);
452 	if (!data)
453 		return -ENOMEM;
454 
455 	spin_lock_bh(&block->profile.lock);
456 	if (block->profile.data) {
457 		data->dasd_io_reqs = block->profile.data->dasd_io_reqs;
458 		data->dasd_io_sects = block->profile.data->dasd_io_sects;
459 		memcpy(data->dasd_io_secs, block->profile.data->dasd_io_secs,
460 		       sizeof(data->dasd_io_secs));
461 		memcpy(data->dasd_io_times, block->profile.data->dasd_io_times,
462 		       sizeof(data->dasd_io_times));
463 		memcpy(data->dasd_io_timps, block->profile.data->dasd_io_timps,
464 		       sizeof(data->dasd_io_timps));
465 		memcpy(data->dasd_io_time1, block->profile.data->dasd_io_time1,
466 		       sizeof(data->dasd_io_time1));
467 		memcpy(data->dasd_io_time2, block->profile.data->dasd_io_time2,
468 		       sizeof(data->dasd_io_time2));
469 		memcpy(data->dasd_io_time2ps,
470 		       block->profile.data->dasd_io_time2ps,
471 		       sizeof(data->dasd_io_time2ps));
472 		memcpy(data->dasd_io_time3, block->profile.data->dasd_io_time3,
473 		       sizeof(data->dasd_io_time3));
474 		memcpy(data->dasd_io_nr_req,
475 		       block->profile.data->dasd_io_nr_req,
476 		       sizeof(data->dasd_io_nr_req));
477 		spin_unlock_bh(&block->profile.lock);
478 	} else {
479 		spin_unlock_bh(&block->profile.lock);
480 		rc = -EIO;
481 		goto out;
482 	}
483 	if (copy_to_user(argp, data, sizeof(*data)))
484 		rc = -EFAULT;
485 out:
486 	kfree(data);
487 	return rc;
488 }
489 #else
490 static int dasd_ioctl_reset_profile(struct dasd_block *block)
491 {
492 	return -ENOTTY;
493 }
494 
495 static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
496 {
497 	return -ENOTTY;
498 }
499 #endif
500 
501 /*
502  * Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
503  */
504 static int __dasd_ioctl_information(struct dasd_block *block,
505 		struct dasd_information2_t *dasd_info)
506 {
507 	struct subchannel_id sch_id;
508 	struct ccw_dev_id dev_id;
509 	struct dasd_device *base;
510 	struct ccw_device *cdev;
511 	struct list_head *l;
512 	unsigned long flags;
513 	int rc;
514 
515 	base = block->base;
516 	if (!base->discipline || !base->discipline->fill_info)
517 		return -EINVAL;
518 
519 	rc = base->discipline->fill_info(base, dasd_info);
520 	if (rc)
521 		return rc;
522 
523 	cdev = base->cdev;
524 	ccw_device_get_id(cdev, &dev_id);
525 	ccw_device_get_schid(cdev, &sch_id);
526 
527 	dasd_info->devno = dev_id.devno;
528 	dasd_info->schid = sch_id.sch_no;
529 	dasd_info->cu_type = cdev->id.cu_type;
530 	dasd_info->cu_model = cdev->id.cu_model;
531 	dasd_info->dev_type = cdev->id.dev_type;
532 	dasd_info->dev_model = cdev->id.dev_model;
533 	dasd_info->status = base->state;
534 	/*
535 	 * The open_count is increased for every opener, that includes
536 	 * the blkdev_get in dasd_scan_partitions.
537 	 * This must be hidden from user-space.
538 	 */
539 	dasd_info->open_count = atomic_read(&block->open_count);
540 	if (!block->bdev)
541 		dasd_info->open_count++;
542 
543 	/*
544 	 * check if device is really formatted
545 	 * LDL / CDL was returned by 'fill_info'
546 	 */
547 	if ((base->state < DASD_STATE_READY) ||
548 	    (dasd_check_blocksize(block->bp_block)))
549 		dasd_info->format = DASD_FORMAT_NONE;
550 
551 	dasd_info->features |=
552 		((base->features & DASD_FEATURE_READONLY) != 0);
553 
554 	memcpy(dasd_info->type, base->discipline->name, 4);
555 
556 	spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
557 	list_for_each(l, &base->ccw_queue)
558 		dasd_info->chanq_len++;
559 	spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
560 	return 0;
561 }
562 
563 static int dasd_ioctl_information(struct dasd_block *block, void __user *argp,
564 		size_t copy_size)
565 {
566 	struct dasd_information2_t *dasd_info;
567 	int error;
568 
569 	dasd_info = kzalloc(sizeof(*dasd_info), GFP_KERNEL);
570 	if (!dasd_info)
571 		return -ENOMEM;
572 
573 	error = __dasd_ioctl_information(block, dasd_info);
574 	if (!error && copy_to_user(argp, dasd_info, copy_size))
575 		error = -EFAULT;
576 	kfree(dasd_info);
577 	return error;
578 }
579 
580 /*
581  * Set read only
582  */
583 int dasd_set_read_only(struct block_device *bdev, bool ro)
584 {
585 	struct dasd_device *base;
586 	int rc;
587 
588 	/* do not manipulate hardware state for partitions */
589 	if (bdev_is_partition(bdev))
590 		return 0;
591 
592 	base = dasd_device_from_gendisk(bdev->bd_disk);
593 	if (!base)
594 		return -ENODEV;
595 	if (!ro && test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
596 		rc = -EROFS;
597 	else
598 		rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, ro);
599 	dasd_put_device(base);
600 	return rc;
601 }
602 
603 static int dasd_ioctl_readall_cmb(struct dasd_block *block, unsigned int cmd,
604 				  struct cmbdata __user *argp)
605 {
606 	size_t size = _IOC_SIZE(cmd);
607 	struct cmbdata data;
608 	int ret;
609 
610 	ret = cmf_readall(block->base->cdev, &data);
611 	if (!ret && copy_to_user(argp, &data, min(size, sizeof(*argp))))
612 		return -EFAULT;
613 	return ret;
614 }
615 
616 int dasd_ioctl(struct block_device *bdev, blk_mode_t mode,
617 	       unsigned int cmd, unsigned long arg)
618 {
619 	struct dasd_block *block;
620 	struct dasd_device *base;
621 	void __user *argp;
622 	int rc;
623 
624 	if (is_compat_task())
625 		argp = compat_ptr(arg);
626 	else
627 		argp = (void __user *)arg;
628 
629 	if ((_IOC_DIR(cmd) != _IOC_NONE) && !arg)
630 		return -EINVAL;
631 
632 	base = dasd_device_from_gendisk(bdev->bd_disk);
633 	if (!base)
634 		return -ENODEV;
635 	block = base->block;
636 	rc = 0;
637 	switch (cmd) {
638 	case BIODASDDISABLE:
639 		rc = dasd_ioctl_disable(bdev);
640 		break;
641 	case BIODASDENABLE:
642 		rc = dasd_ioctl_enable(bdev);
643 		break;
644 	case BIODASDQUIESCE:
645 		rc = dasd_ioctl_quiesce(block);
646 		break;
647 	case BIODASDRESUME:
648 		rc = dasd_ioctl_resume(block);
649 		break;
650 	case BIODASDABORTIO:
651 		rc = dasd_ioctl_abortio(block);
652 		break;
653 	case BIODASDALLOWIO:
654 		rc = dasd_ioctl_allowio(block);
655 		break;
656 	case BIODASDFMT:
657 		rc = dasd_ioctl_format(bdev, argp);
658 		break;
659 	case BIODASDCHECKFMT:
660 		rc = dasd_ioctl_check_format(bdev, argp);
661 		break;
662 	case BIODASDINFO:
663 		rc = dasd_ioctl_information(block, argp,
664 				sizeof(struct dasd_information_t));
665 		break;
666 	case BIODASDINFO2:
667 		rc = dasd_ioctl_information(block, argp,
668 				sizeof(struct dasd_information2_t));
669 		break;
670 	case BIODASDPRRD:
671 		rc = dasd_ioctl_read_profile(block, argp);
672 		break;
673 	case BIODASDPRRST:
674 		rc = dasd_ioctl_reset_profile(block);
675 		break;
676 	case DASDAPIVER:
677 		rc = dasd_ioctl_api_version(argp);
678 		break;
679 	case BIODASDCMFENABLE:
680 		rc = enable_cmf(base->cdev);
681 		break;
682 	case BIODASDCMFDISABLE:
683 		rc = disable_cmf(base->cdev);
684 		break;
685 	case BIODASDREADALLCMB:
686 		rc = dasd_ioctl_readall_cmb(block, cmd, argp);
687 		break;
688 	case BIODASDRAS:
689 		rc = dasd_ioctl_release_space(bdev, argp);
690 		break;
691 	case BIODASDCOPYPAIRSWAP:
692 		rc = dasd_ioctl_copy_pair_swap(bdev, argp);
693 		break;
694 	default:
695 		/* if the discipline has an ioctl method try it. */
696 		rc = -ENOTTY;
697 		if (base->discipline->ioctl)
698 			rc = base->discipline->ioctl(block, cmd, argp);
699 	}
700 	dasd_put_device(base);
701 	return rc;
702 }
703 
704 
705 /**
706  * dasd_biodasdinfo() - fill out the dasd information structure
707  * @disk: [in] pointer to gendisk structure that references a DASD
708  * @info: [out] pointer to the dasd_information2_t structure
709  *
710  * Provide access to DASD specific information.
711  * The gendisk structure is checked if it belongs to the DASD driver by
712  * comparing the gendisk->fops pointer.
713  * If it does not belong to the DASD driver -EINVAL is returned.
714  * Otherwise the provided dasd_information2_t structure is filled out.
715  *
716  * Returns:
717  *   %0 on success and a negative error value on failure.
718  */
719 int dasd_biodasdinfo(struct gendisk *disk, struct dasd_information2_t *info)
720 {
721 	struct dasd_device *base;
722 	int error;
723 
724 	if (disk->fops != &dasd_device_operations)
725 		return -EINVAL;
726 
727 	base = dasd_device_from_gendisk(disk);
728 	if (!base)
729 		return -ENODEV;
730 	error = __dasd_ioctl_information(base->block, info);
731 	dasd_put_device(base);
732 	return error;
733 }
734 /* export that symbol_get in partition detection is possible */
735 EXPORT_SYMBOL_GPL(dasd_biodasdinfo);
736