xref: /linux/drivers/s390/block/dasd_ioctl.c (revision 7a9787e1eba95a166265e6a260cf30af04ef0a99)
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/interrupt.h>
13 #include <linux/major.h>
14 #include <linux/fs.h>
15 #include <linux/blkpg.h>
16 
17 #include <asm/ccwdev.h>
18 #include <asm/cmb.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 static int
28 dasd_ioctl_api_version(void __user *argp)
29 {
30 	int ver = DASD_API_VERSION;
31 	return put_user(ver, (int __user *)argp);
32 }
33 
34 /*
35  * Enable device.
36  * used by dasdfmt after BIODASDDISABLE to retrigger blocksize detection
37  */
38 static int
39 dasd_ioctl_enable(struct block_device *bdev)
40 {
41 	struct dasd_block *block = bdev->bd_disk->private_data;
42 
43 	if (!capable(CAP_SYS_ADMIN))
44 		return -EACCES;
45 
46 	dasd_enable_device(block->base);
47 	/* Formatting the dasd device can change the capacity. */
48 	mutex_lock(&bdev->bd_mutex);
49 	i_size_write(bdev->bd_inode, (loff_t)get_capacity(block->gdp) << 9);
50 	mutex_unlock(&bdev->bd_mutex);
51 	return 0;
52 }
53 
54 /*
55  * Disable device.
56  * Used by dasdfmt. Disable I/O operations but allow ioctls.
57  */
58 static int
59 dasd_ioctl_disable(struct block_device *bdev)
60 {
61 	struct dasd_block *block = bdev->bd_disk->private_data;
62 
63 	if (!capable(CAP_SYS_ADMIN))
64 		return -EACCES;
65 
66 	/*
67 	 * Man this is sick. We don't do a real disable but only downgrade
68 	 * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
69 	 * BIODASDDISABLE to disable accesses to the device via the block
70 	 * device layer but it still wants to do i/o on the device by
71 	 * using the BIODASDFMT ioctl. Therefore the correct state for the
72 	 * device is DASD_STATE_BASIC that allows to do basic i/o.
73 	 */
74 	dasd_set_target_state(block->base, DASD_STATE_BASIC);
75 	/*
76 	 * Set i_size to zero, since read, write, etc. check against this
77 	 * value.
78 	 */
79 	mutex_lock(&bdev->bd_mutex);
80 	i_size_write(bdev->bd_inode, 0);
81 	mutex_unlock(&bdev->bd_mutex);
82 	return 0;
83 }
84 
85 /*
86  * Quiesce device.
87  */
88 static int dasd_ioctl_quiesce(struct dasd_block *block)
89 {
90 	unsigned long flags;
91 	struct dasd_device *base;
92 
93 	base = block->base;
94 	if (!capable (CAP_SYS_ADMIN))
95 		return -EACCES;
96 
97 	DEV_MESSAGE(KERN_DEBUG, base, "%s", "Quiesce IO on device");
98 	spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
99 	base->stopped |= DASD_STOPPED_QUIESCE;
100 	spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
101 	return 0;
102 }
103 
104 
105 /*
106  * Quiesce device.
107  */
108 static int dasd_ioctl_resume(struct dasd_block *block)
109 {
110 	unsigned long flags;
111 	struct dasd_device *base;
112 
113 	base = block->base;
114 	if (!capable (CAP_SYS_ADMIN))
115 		return -EACCES;
116 
117 	DEV_MESSAGE(KERN_DEBUG, base, "%s", "resume IO on device");
118 	spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
119 	base->stopped &= ~DASD_STOPPED_QUIESCE;
120 	spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
121 
122 	dasd_schedule_block_bh(block);
123 	return 0;
124 }
125 
126 /*
127  * performs formatting of _device_ according to _fdata_
128  * Note: The discipline's format_function is assumed to deliver formatting
129  * commands to format a single unit of the device. In terms of the ECKD
130  * devices this means CCWs are generated to format a single track.
131  */
132 static int dasd_format(struct dasd_block *block, struct format_data_t *fdata)
133 {
134 	struct dasd_ccw_req *cqr;
135 	struct dasd_device *base;
136 	int rc;
137 
138 	base = block->base;
139 	if (base->discipline->format_device == NULL)
140 		return -EPERM;
141 
142 	if (base->state != DASD_STATE_BASIC) {
143 		DEV_MESSAGE(KERN_WARNING, base, "%s",
144 			    "dasd_format: device is not disabled! ");
145 		return -EBUSY;
146 	}
147 
148 	DBF_DEV_EVENT(DBF_NOTICE, base,
149 		      "formatting units %d to %d (%d B blocks) flags %d",
150 		      fdata->start_unit,
151 		      fdata->stop_unit, fdata->blksize, fdata->intensity);
152 
153 	/* Since dasdfmt keeps the device open after it was disabled,
154 	 * there still exists an inode for this device.
155 	 * We must update i_blkbits, otherwise we might get errors when
156 	 * enabling the device later.
157 	 */
158 	if (fdata->start_unit == 0) {
159 		struct block_device *bdev = bdget_disk(block->gdp, 0);
160 		bdev->bd_inode->i_blkbits = blksize_bits(fdata->blksize);
161 		bdput(bdev);
162 	}
163 
164 	while (fdata->start_unit <= fdata->stop_unit) {
165 		cqr = base->discipline->format_device(base, fdata);
166 		if (IS_ERR(cqr))
167 			return PTR_ERR(cqr);
168 		rc = dasd_sleep_on_interruptible(cqr);
169 		dasd_sfree_request(cqr, cqr->memdev);
170 		if (rc) {
171 			if (rc != -ERESTARTSYS)
172 				DEV_MESSAGE(KERN_ERR, base,
173 					    " Formatting of unit %d failed "
174 					    "with rc = %d",
175 					    fdata->start_unit, rc);
176 			return rc;
177 		}
178 		fdata->start_unit++;
179 	}
180 	return 0;
181 }
182 
183 /*
184  * Format device.
185  */
186 static int
187 dasd_ioctl_format(struct block_device *bdev, void __user *argp)
188 {
189 	struct dasd_block *block = bdev->bd_disk->private_data;
190 	struct format_data_t fdata;
191 
192 	if (!capable(CAP_SYS_ADMIN))
193 		return -EACCES;
194 	if (!argp)
195 		return -EINVAL;
196 
197 	if (block->base->features & DASD_FEATURE_READONLY)
198 		return -EROFS;
199 	if (copy_from_user(&fdata, argp, sizeof(struct format_data_t)))
200 		return -EFAULT;
201 	if (bdev != bdev->bd_contains) {
202 		DEV_MESSAGE(KERN_WARNING, block->base, "%s",
203 			    "Cannot low-level format a partition");
204 		return -EINVAL;
205 	}
206 	return dasd_format(block, &fdata);
207 }
208 
209 #ifdef CONFIG_DASD_PROFILE
210 /*
211  * Reset device profile information
212  */
213 static int dasd_ioctl_reset_profile(struct dasd_block *block)
214 {
215 	memset(&block->profile, 0, sizeof(struct dasd_profile_info_t));
216 	return 0;
217 }
218 
219 /*
220  * Return device profile information
221  */
222 static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
223 {
224 	if (dasd_profile_level == DASD_PROFILE_OFF)
225 		return -EIO;
226 	if (copy_to_user(argp, &block->profile,
227 			 sizeof(struct dasd_profile_info_t)))
228 		return -EFAULT;
229 	return 0;
230 }
231 #else
232 static int dasd_ioctl_reset_profile(struct dasd_block *block)
233 {
234 	return -ENOSYS;
235 }
236 
237 static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
238 {
239 	return -ENOSYS;
240 }
241 #endif
242 
243 /*
244  * Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
245  */
246 static int dasd_ioctl_information(struct dasd_block *block,
247 				  unsigned int cmd, void __user *argp)
248 {
249 	struct dasd_information2_t *dasd_info;
250 	unsigned long flags;
251 	int rc;
252 	struct dasd_device *base;
253 	struct ccw_device *cdev;
254 	struct ccw_dev_id dev_id;
255 
256 	base = block->base;
257 	if (!base->discipline->fill_info)
258 		return -EINVAL;
259 
260 	dasd_info = kzalloc(sizeof(struct dasd_information2_t), GFP_KERNEL);
261 	if (dasd_info == NULL)
262 		return -ENOMEM;
263 
264 	rc = base->discipline->fill_info(base, dasd_info);
265 	if (rc) {
266 		kfree(dasd_info);
267 		return rc;
268 	}
269 
270 	cdev = base->cdev;
271 	ccw_device_get_id(cdev, &dev_id);
272 
273 	dasd_info->devno = dev_id.devno;
274 	dasd_info->schid = _ccw_device_get_subchannel_number(base->cdev);
275 	dasd_info->cu_type = cdev->id.cu_type;
276 	dasd_info->cu_model = cdev->id.cu_model;
277 	dasd_info->dev_type = cdev->id.dev_type;
278 	dasd_info->dev_model = cdev->id.dev_model;
279 	dasd_info->status = base->state;
280 	/*
281 	 * The open_count is increased for every opener, that includes
282 	 * the blkdev_get in dasd_scan_partitions.
283 	 * This must be hidden from user-space.
284 	 */
285 	dasd_info->open_count = atomic_read(&block->open_count);
286 	if (!block->bdev)
287 		dasd_info->open_count++;
288 
289 	/*
290 	 * check if device is really formatted
291 	 * LDL / CDL was returned by 'fill_info'
292 	 */
293 	if ((base->state < DASD_STATE_READY) ||
294 	    (dasd_check_blocksize(block->bp_block)))
295 		dasd_info->format = DASD_FORMAT_NONE;
296 
297 	dasd_info->features |=
298 		((base->features & DASD_FEATURE_READONLY) != 0);
299 
300 	if (base->discipline)
301 		memcpy(dasd_info->type, base->discipline->name, 4);
302 	else
303 		memcpy(dasd_info->type, "none", 4);
304 
305 	if (block->request_queue->request_fn) {
306 		struct list_head *l;
307 #ifdef DASD_EXTENDED_PROFILING
308 		{
309 			struct list_head *l;
310 			spin_lock_irqsave(&block->lock, flags);
311 			list_for_each(l, &block->request_queue->queue_head)
312 				dasd_info->req_queue_len++;
313 			spin_unlock_irqrestore(&block->lock, flags);
314 		}
315 #endif				/* DASD_EXTENDED_PROFILING */
316 		spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
317 		list_for_each(l, &base->ccw_queue)
318 			dasd_info->chanq_len++;
319 		spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
320 				       flags);
321 	}
322 
323 	rc = 0;
324 	if (copy_to_user(argp, dasd_info,
325 			 ((cmd == (unsigned int) BIODASDINFO2) ?
326 			  sizeof(struct dasd_information2_t) :
327 			  sizeof(struct dasd_information_t))))
328 		rc = -EFAULT;
329 	kfree(dasd_info);
330 	return rc;
331 }
332 
333 /*
334  * Set read only
335  */
336 static int
337 dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
338 {
339 	struct dasd_block *block =  bdev->bd_disk->private_data;
340 	int intval;
341 
342 	if (!capable(CAP_SYS_ADMIN))
343 		return -EACCES;
344 	if (bdev != bdev->bd_contains)
345 		// ro setting is not allowed for partitions
346 		return -EINVAL;
347 	if (get_user(intval, (int __user *)argp))
348 		return -EFAULT;
349 
350 	set_disk_ro(bdev->bd_disk, intval);
351 	return dasd_set_feature(block->base->cdev, DASD_FEATURE_READONLY, intval);
352 }
353 
354 static int dasd_ioctl_readall_cmb(struct dasd_block *block, unsigned int cmd,
355 		unsigned long arg)
356 {
357 	struct cmbdata __user *argp = (void __user *) arg;
358 	size_t size = _IOC_SIZE(cmd);
359 	struct cmbdata data;
360 	int ret;
361 
362 	ret = cmf_readall(block->base->cdev, &data);
363 	if (!ret && copy_to_user(argp, &data, min(size, sizeof(*argp))))
364 		return -EFAULT;
365 	return ret;
366 }
367 
368 int
369 dasd_ioctl(struct block_device *bdev, fmode_t mode,
370 	   unsigned int cmd, unsigned long arg)
371 {
372 	struct dasd_block *block = bdev->bd_disk->private_data;
373 	void __user *argp = (void __user *)arg;
374 
375 	if (!block)
376                 return -ENODEV;
377 
378 	if ((_IOC_DIR(cmd) != _IOC_NONE) && !arg) {
379 		PRINT_DEBUG("empty data ptr");
380 		return -EINVAL;
381 	}
382 
383 	switch (cmd) {
384 	case BIODASDDISABLE:
385 		return dasd_ioctl_disable(bdev);
386 	case BIODASDENABLE:
387 		return dasd_ioctl_enable(bdev);
388 	case BIODASDQUIESCE:
389 		return dasd_ioctl_quiesce(block);
390 	case BIODASDRESUME:
391 		return dasd_ioctl_resume(block);
392 	case BIODASDFMT:
393 		return dasd_ioctl_format(bdev, argp);
394 	case BIODASDINFO:
395 		return dasd_ioctl_information(block, cmd, argp);
396 	case BIODASDINFO2:
397 		return dasd_ioctl_information(block, cmd, argp);
398 	case BIODASDPRRD:
399 		return dasd_ioctl_read_profile(block, argp);
400 	case BIODASDPRRST:
401 		return dasd_ioctl_reset_profile(block);
402 	case BLKROSET:
403 		return dasd_ioctl_set_ro(bdev, argp);
404 	case DASDAPIVER:
405 		return dasd_ioctl_api_version(argp);
406 	case BIODASDCMFENABLE:
407 		return enable_cmf(block->base->cdev);
408 	case BIODASDCMFDISABLE:
409 		return disable_cmf(block->base->cdev);
410 	case BIODASDREADALLCMB:
411 		return dasd_ioctl_readall_cmb(block, cmd, arg);
412 	default:
413 		/* if the discipline has an ioctl method try it. */
414 		if (block->base->discipline->ioctl) {
415 			int rval = block->base->discipline->ioctl(block, cmd, argp);
416 			if (rval != -ENOIOCTLCMD)
417 				return rval;
418 		}
419 
420 		return -EINVAL;
421 	}
422 }
423