xref: /openbmc/linux/drivers/s390/block/dasd_ioctl.c (revision 87c2ce3b) 
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  * $Revision: 1.50 $
11  *
12  * i/o controls for the dasd driver.
13  */
14 #include <linux/config.h>
15 #include <linux/interrupt.h>
16 #include <linux/major.h>
17 #include <linux/fs.h>
18 #include <linux/blkpg.h>
19 
20 #include <asm/ccwdev.h>
21 #include <asm/uaccess.h>
22 
23 /* This is ugly... */
24 #define PRINTK_HEADER "dasd_ioctl:"
25 
26 #include "dasd_int.h"
27 
28 /*
29  * SECTION: ioctl functions.
30  */
31 static struct list_head dasd_ioctl_list = LIST_HEAD_INIT(dasd_ioctl_list);
32 
33 /*
34  * Find the ioctl with number no.
35  */
36 static struct dasd_ioctl *
37 dasd_find_ioctl(int no)
38 {
39 	struct dasd_ioctl *ioctl;
40 
41 	list_for_each_entry (ioctl, &dasd_ioctl_list, list)
42 		if (ioctl->no == no)
43 			return ioctl;
44 	return NULL;
45 }
46 
47 /*
48  * Register ioctl with number no.
49  */
50 int
51 dasd_ioctl_no_register(struct module *owner, int no, dasd_ioctl_fn_t handler)
52 {
53 	struct dasd_ioctl *new;
54 	if (dasd_find_ioctl(no))
55 		return -EBUSY;
56 	new = kmalloc(sizeof (struct dasd_ioctl), GFP_KERNEL);
57 	if (new == NULL)
58 		return -ENOMEM;
59 	new->owner = owner;
60 	new->no = no;
61 	new->handler = handler;
62 	list_add(&new->list, &dasd_ioctl_list);
63 	return 0;
64 }
65 
66 /*
67  * Deregister ioctl with number no.
68  */
69 int
70 dasd_ioctl_no_unregister(struct module *owner, int no, dasd_ioctl_fn_t handler)
71 {
72 	struct dasd_ioctl *old = dasd_find_ioctl(no);
73 	if (old == NULL)
74 		return -ENOENT;
75 	if (old->no != no || old->handler != handler || owner != old->owner)
76 		return -EINVAL;
77 	list_del(&old->list);
78 	kfree(old);
79 	return 0;
80 }
81 
82 int
83 dasd_ioctl(struct inode *inp, struct file *filp,
84 	   unsigned int no, unsigned long data)
85 {
86 	struct block_device *bdev = inp->i_bdev;
87 	struct dasd_device *device = bdev->bd_disk->private_data;
88 	struct dasd_ioctl *ioctl;
89 	const char *dir;
90 	int rc;
91 
92 	if ((_IOC_DIR(no) != _IOC_NONE) && (data == 0)) {
93 		PRINT_DEBUG("empty data ptr");
94 		return -EINVAL;
95 	}
96 	dir = _IOC_DIR (no) == _IOC_NONE ? "0" :
97 		_IOC_DIR (no) == _IOC_READ ? "r" :
98 		_IOC_DIR (no) == _IOC_WRITE ? "w" :
99 		_IOC_DIR (no) == (_IOC_READ | _IOC_WRITE) ? "rw" : "u";
100 	DBF_DEV_EVENT(DBF_DEBUG, device,
101 		      "ioctl 0x%08x %s'0x%x'%d(%d) with data %8lx", no,
102 		      dir, _IOC_TYPE(no), _IOC_NR(no), _IOC_SIZE(no), data);
103 	/* Search for ioctl no in the ioctl list. */
104 	list_for_each_entry(ioctl, &dasd_ioctl_list, list) {
105 		if (ioctl->no == no) {
106 			/* Found a matching ioctl. Call it. */
107 			if (!try_module_get(ioctl->owner))
108 				continue;
109 			rc = ioctl->handler(bdev, no, data);
110 			module_put(ioctl->owner);
111 			return rc;
112 		}
113 	}
114 	/* No ioctl with number no. */
115 	DBF_DEV_EVENT(DBF_INFO, device,
116 		      "unknown ioctl 0x%08x=%s'0x%x'%d(%d) data %8lx", no,
117 		      dir, _IOC_TYPE(no), _IOC_NR(no), _IOC_SIZE(no), data);
118 	return -EINVAL;
119 }
120 
121 long
122 dasd_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
123 {
124 	int rval;
125 
126 	lock_kernel();
127 	rval = dasd_ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
128 	unlock_kernel();
129 
130 	return (rval == -EINVAL) ? -ENOIOCTLCMD : rval;
131 }
132 
133 static int
134 dasd_ioctl_api_version(struct block_device *bdev, int no, long args)
135 {
136 	int ver = DASD_API_VERSION;
137 	return put_user(ver, (int __user *) args);
138 }
139 
140 /*
141  * Enable device.
142  * used by dasdfmt after BIODASDDISABLE to retrigger blocksize detection
143  */
144 static int
145 dasd_ioctl_enable(struct block_device *bdev, int no, long args)
146 {
147 	struct dasd_device *device;
148 
149 	if (!capable(CAP_SYS_ADMIN))
150 		return -EACCES;
151 	device = bdev->bd_disk->private_data;
152 	if (device == NULL)
153 		return -ENODEV;
154 	dasd_enable_device(device);
155 	/* Formatting the dasd device can change the capacity. */
156 	down(&bdev->bd_sem);
157 	i_size_write(bdev->bd_inode, (loff_t)get_capacity(device->gdp) << 9);
158 	up(&bdev->bd_sem);
159 	return 0;
160 }
161 
162 /*
163  * Disable device.
164  * Used by dasdfmt. Disable I/O operations but allow ioctls.
165  */
166 static int
167 dasd_ioctl_disable(struct block_device *bdev, int no, long args)
168 {
169 	struct dasd_device *device;
170 
171 	if (!capable(CAP_SYS_ADMIN))
172 		return -EACCES;
173 	device = bdev->bd_disk->private_data;
174 	if (device == NULL)
175 		return -ENODEV;
176 	/*
177 	 * Man this is sick. We don't do a real disable but only downgrade
178 	 * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
179 	 * BIODASDDISABLE to disable accesses to the device via the block
180 	 * device layer but it still wants to do i/o on the device by
181 	 * using the BIODASDFMT ioctl. Therefore the correct state for the
182 	 * device is DASD_STATE_BASIC that allows to do basic i/o.
183 	 */
184 	dasd_set_target_state(device, DASD_STATE_BASIC);
185 	/*
186 	 * Set i_size to zero, since read, write, etc. check against this
187 	 * value.
188 	 */
189 	down(&bdev->bd_sem);
190 	i_size_write(bdev->bd_inode, 0);
191 	up(&bdev->bd_sem);
192 	return 0;
193 }
194 
195 /*
196  * Quiesce device.
197  */
198 static int
199 dasd_ioctl_quiesce(struct block_device *bdev, int no, long args)
200 {
201 	struct dasd_device *device;
202 	unsigned long flags;
203 
204 	if (!capable (CAP_SYS_ADMIN))
205 		return -EACCES;
206 
207 	device = bdev->bd_disk->private_data;
208 	if (device == NULL)
209 		return -ENODEV;
210 
211 	DEV_MESSAGE (KERN_DEBUG, device, "%s",
212 		     "Quiesce IO on device");
213 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
214 	device->stopped |= DASD_STOPPED_QUIESCE;
215 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
216 	return 0;
217 }
218 
219 
220 /*
221  * Quiesce device.
222  */
223 static int
224 dasd_ioctl_resume(struct block_device *bdev, int no, long args)
225 {
226 	struct dasd_device *device;
227 	unsigned long flags;
228 
229 	if (!capable (CAP_SYS_ADMIN))
230 		return -EACCES;
231 
232 	device = bdev->bd_disk->private_data;
233 	if (device == NULL)
234 		return -ENODEV;
235 
236 	DEV_MESSAGE (KERN_DEBUG, device, "%s",
237 		     "resume IO on device");
238 
239 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
240 	device->stopped &= ~DASD_STOPPED_QUIESCE;
241 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
242 
243 	dasd_schedule_bh (device);
244 	return 0;
245 }
246 
247 /*
248  * performs formatting of _device_ according to _fdata_
249  * Note: The discipline's format_function is assumed to deliver formatting
250  * commands to format a single unit of the device. In terms of the ECKD
251  * devices this means CCWs are generated to format a single track.
252  */
253 static int
254 dasd_format(struct dasd_device * device, struct format_data_t * fdata)
255 {
256 	struct dasd_ccw_req *cqr;
257 	int rc;
258 
259 	if (device->discipline->format_device == NULL)
260 		return -EPERM;
261 
262 	if (device->state != DASD_STATE_BASIC) {
263 		DEV_MESSAGE(KERN_WARNING, device, "%s",
264 			    "dasd_format: device is not disabled! ");
265 		return -EBUSY;
266 	}
267 
268 	DBF_DEV_EVENT(DBF_NOTICE, device,
269 		      "formatting units %d to %d (%d B blocks) flags %d",
270 		      fdata->start_unit,
271 		      fdata->stop_unit, fdata->blksize, fdata->intensity);
272 
273 	/* Since dasdfmt keeps the device open after it was disabled,
274 	 * there still exists an inode for this device.
275 	 * We must update i_blkbits, otherwise we might get errors when
276 	 * enabling the device later.
277 	 */
278 	if (fdata->start_unit == 0) {
279 		struct block_device *bdev = bdget_disk(device->gdp, 0);
280 		bdev->bd_inode->i_blkbits = blksize_bits(fdata->blksize);
281 		bdput(bdev);
282 	}
283 
284 	while (fdata->start_unit <= fdata->stop_unit) {
285 		cqr = device->discipline->format_device(device, fdata);
286 		if (IS_ERR(cqr))
287 			return PTR_ERR(cqr);
288 		rc = dasd_sleep_on_interruptible(cqr);
289 		dasd_sfree_request(cqr, cqr->device);
290 		if (rc) {
291 			if (rc != -ERESTARTSYS)
292 				DEV_MESSAGE(KERN_ERR, device,
293 					    " Formatting of unit %d failed "
294 					    "with rc = %d",
295 					    fdata->start_unit, rc);
296 			return rc;
297 		}
298 		fdata->start_unit++;
299 	}
300 	return 0;
301 }
302 
303 /*
304  * Format device.
305  */
306 static int
307 dasd_ioctl_format(struct block_device *bdev, int no, long args)
308 {
309 	struct dasd_device *device;
310 	struct format_data_t fdata;
311 
312 	if (!capable(CAP_SYS_ADMIN))
313 		return -EACCES;
314 	if (!args)
315 		return -EINVAL;
316 	/* fdata == NULL is no longer a valid arg to dasd_format ! */
317 	device = bdev->bd_disk->private_data;
318 
319 	if (device == NULL)
320 		return -ENODEV;
321 
322 	if (device->features & DASD_FEATURE_READONLY)
323 		return -EROFS;
324 	if (copy_from_user(&fdata, (void __user *) args,
325 			   sizeof (struct format_data_t)))
326 		return -EFAULT;
327 	if (bdev != bdev->bd_contains) {
328 		DEV_MESSAGE(KERN_WARNING, device, "%s",
329 			    "Cannot low-level format a partition");
330 		return -EINVAL;
331 	}
332 	return dasd_format(device, &fdata);
333 }
334 
335 #ifdef CONFIG_DASD_PROFILE
336 /*
337  * Reset device profile information
338  */
339 static int
340 dasd_ioctl_reset_profile(struct block_device *bdev, int no, long args)
341 {
342 	struct dasd_device *device;
343 
344 	if (!capable(CAP_SYS_ADMIN))
345 		return -EACCES;
346 
347 	device = bdev->bd_disk->private_data;
348 	if (device == NULL)
349 		return -ENODEV;
350 
351 	memset(&device->profile, 0, sizeof (struct dasd_profile_info_t));
352 	return 0;
353 }
354 
355 /*
356  * Return device profile information
357  */
358 static int
359 dasd_ioctl_read_profile(struct block_device *bdev, int no, long args)
360 {
361 	struct dasd_device *device;
362 
363 	device = bdev->bd_disk->private_data;
364 	if (device == NULL)
365 		return -ENODEV;
366 
367 	if (dasd_profile_level == DASD_PROFILE_OFF)
368 		return -EIO;
369 
370 	if (copy_to_user((long __user *) args, (long *) &device->profile,
371 			 sizeof (struct dasd_profile_info_t)))
372 		return -EFAULT;
373 	return 0;
374 }
375 #else
376 static int
377 dasd_ioctl_reset_profile(struct block_device *bdev, int no, long args)
378 {
379 	return -ENOSYS;
380 }
381 
382 static int
383 dasd_ioctl_read_profile(struct block_device *bdev, int no, long args)
384 {
385 	return -ENOSYS;
386 }
387 #endif
388 
389 /*
390  * Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
391  */
392 static int
393 dasd_ioctl_information(struct block_device *bdev, int no, long args)
394 {
395 	struct dasd_device *device;
396 	struct dasd_information2_t *dasd_info;
397 	unsigned long flags;
398 	int rc;
399 	struct ccw_device *cdev;
400 
401 	device = bdev->bd_disk->private_data;
402 	if (device == NULL)
403 		return -ENODEV;
404 
405 	if (!device->discipline->fill_info)
406 		return -EINVAL;
407 
408 	dasd_info = kmalloc(sizeof(struct dasd_information2_t), GFP_KERNEL);
409 	if (dasd_info == NULL)
410 		return -ENOMEM;
411 
412 	rc = device->discipline->fill_info(device, dasd_info);
413 	if (rc) {
414 		kfree(dasd_info);
415 		return rc;
416 	}
417 
418 	cdev = device->cdev;
419 
420 	dasd_info->devno = _ccw_device_get_device_number(device->cdev);
421 	dasd_info->schid = _ccw_device_get_subchannel_number(device->cdev);
422 	dasd_info->cu_type = cdev->id.cu_type;
423 	dasd_info->cu_model = cdev->id.cu_model;
424 	dasd_info->dev_type = cdev->id.dev_type;
425 	dasd_info->dev_model = cdev->id.dev_model;
426 	dasd_info->open_count = atomic_read(&device->open_count);
427 	dasd_info->status = device->state;
428 
429 	/*
430 	 * check if device is really formatted
431 	 * LDL / CDL was returned by 'fill_info'
432 	 */
433 	if ((device->state < DASD_STATE_READY) ||
434 	    (dasd_check_blocksize(device->bp_block)))
435 		dasd_info->format = DASD_FORMAT_NONE;
436 
437 	dasd_info->features |=
438 		((device->features & DASD_FEATURE_READONLY) != 0);
439 
440 	if (device->discipline)
441 		memcpy(dasd_info->type, device->discipline->name, 4);
442 	else
443 		memcpy(dasd_info->type, "none", 4);
444 	dasd_info->req_queue_len = 0;
445 	dasd_info->chanq_len = 0;
446 	if (device->request_queue->request_fn) {
447 		struct list_head *l;
448 #ifdef DASD_EXTENDED_PROFILING
449 		{
450 			struct list_head *l;
451 			spin_lock_irqsave(&device->lock, flags);
452 			list_for_each(l, &device->request_queue->queue_head)
453 				dasd_info->req_queue_len++;
454 			spin_unlock_irqrestore(&device->lock, flags);
455 		}
456 #endif				/* DASD_EXTENDED_PROFILING */
457 		spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
458 		list_for_each(l, &device->ccw_queue)
459 			dasd_info->chanq_len++;
460 		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev),
461 				       flags);
462 	}
463 
464 	rc = 0;
465 	if (copy_to_user((long __user *) args, (long *) dasd_info,
466 			 ((no == (unsigned int) BIODASDINFO2) ?
467 			  sizeof (struct dasd_information2_t) :
468 			  sizeof (struct dasd_information_t))))
469 		rc = -EFAULT;
470 	kfree(dasd_info);
471 	return rc;
472 }
473 
474 /*
475  * Set read only
476  */
477 static int
478 dasd_ioctl_set_ro(struct block_device *bdev, int no, long args)
479 {
480 	struct dasd_device *device;
481 	int intval, rc;
482 
483 	if (!capable(CAP_SYS_ADMIN))
484 		return -EACCES;
485 	if (bdev != bdev->bd_contains)
486 		// ro setting is not allowed for partitions
487 		return -EINVAL;
488 	if (get_user(intval, (int __user *) args))
489 		return -EFAULT;
490 	device =  bdev->bd_disk->private_data;
491 	if (device == NULL)
492 		return -ENODEV;
493 
494 	set_disk_ro(bdev->bd_disk, intval);
495 	rc = dasd_set_feature(device->cdev, DASD_FEATURE_READONLY, intval);
496 
497 	return rc;
498 }
499 
500 /*
501  * List of static ioctls.
502  */
503 static struct { int no; dasd_ioctl_fn_t fn; } dasd_ioctls[] =
504 {
505 	{ BIODASDDISABLE, dasd_ioctl_disable },
506 	{ BIODASDENABLE, dasd_ioctl_enable },
507 	{ BIODASDQUIESCE, dasd_ioctl_quiesce },
508 	{ BIODASDRESUME, dasd_ioctl_resume },
509 	{ BIODASDFMT, dasd_ioctl_format },
510 	{ BIODASDINFO, dasd_ioctl_information },
511 	{ BIODASDINFO2, dasd_ioctl_information },
512 	{ BIODASDPRRD, dasd_ioctl_read_profile },
513 	{ BIODASDPRRST, dasd_ioctl_reset_profile },
514 	{ BLKROSET, dasd_ioctl_set_ro },
515 	{ DASDAPIVER, dasd_ioctl_api_version },
516 	{ -1, NULL }
517 };
518 
519 int
520 dasd_ioctl_init(void)
521 {
522 	int i;
523 
524 	for (i = 0; dasd_ioctls[i].no != -1; i++)
525 		dasd_ioctl_no_register(NULL, dasd_ioctls[i].no,
526 				       dasd_ioctls[i].fn);
527 	return 0;
528 
529 }
530 
531 void
532 dasd_ioctl_exit(void)
533 {
534 	int i;
535 
536 	for (i = 0; dasd_ioctls[i].no != -1; i++)
537 		dasd_ioctl_no_unregister(NULL, dasd_ioctls[i].no,
538 					 dasd_ioctls[i].fn);
539 
540 }
541 
542 EXPORT_SYMBOL(dasd_ioctl_no_register);
543 EXPORT_SYMBOL(dasd_ioctl_no_unregister);
544