xref: /openbmc/linux/drivers/s390/block/dasd_ioctl.c (revision 1da177e4) 
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);
555